test(ai): expand unit and functional coverage for /ai feature

Unit tests (tests/unittests/test_ai_client.c): +50 cases on top of the
existing 50 — total 100. Covers:
  - chat response parser (ai_parse_response): OpenAI content + Perplexity
    text formats, escape decoding, empty/null/missing inputs, format-string
    safety, multiline content
  - error envelope parser (ai_parse_error_message): standard envelope,
    nested escapes, missing fields, null/empty
  - extended JSON escape: \b, \f, \r, all-specials, UTF-8 pass-through
  - provider autocomplete cycling with >=2 matches and wrap-around
  - session edge cases: NULL args, 100-message order preservation,
    set_model(NULL), ref/unref(NULL)
  - provider edge cases: get/remove with NULL, double-remove, survival
    via session ref after ai_remove_provider
  - settings: multi-key independence, missing key, cross-provider
    isolation
  - model parsing edges: data not array, empty data, "id" outside data,
    multiple models
  - prefs round-trip: set token -> shutdown -> init -> token reloaded
    from disk (uses load_preferences fixture)

Functional tests:
  - Tier A (test_ai.c): 15 cases for the /ai command surface that don't
    need HTTP. Covers /ai help, providers list, set provider/token,
    start with/without key/unknown provider, clear, remove, default
    provider/model, switch without window, bad subcommand.
  - Tier B (test_ai_http.c + ai_http_stub.{c,h,py}): 5 cases that
    exercise the libcurl path against a local Python HTTP stub. The
    stub serves canned bodies in five modes (ok, openai, 401, 500,
    models) so each chat/models/error path is hit end-to-end without
    network.

Infrastructure:
  - TEST_GROUPS bumped to 5 in proftest.c; AI tests live in their own
    Group 5 because mixing them with stabber-driven tests in Group 4
    poisoned stbbr_stop() teardown.
  - PROF_FUNC_TEST_AI macro in functionaltests.c registers AI tests
    with ai_init_test() which wraps init_prof_test with a prof_connect()
    so stabber sees a graceful disconnect at teardown.
  - dist_check_DATA ships ai_http_stub.py with the source tarball.

Source-level changes to enable testing:
  - src/ai/ai_client.{c,h}: dropped 'static' from _parse_ai_response
    (renamed ai_parse_response) and _parse_error_response (renamed
    ai_parse_error_message); declared under a "Parsing helpers (exposed
    for testing)" section. Same approach as ai_parse_models_from_json.

Results in Docker (cproof-debian image):
  - 595/595 unit tests pass
  - 20/20 AI functional tests pass (Group 5)

Makefile.am

@@ -203,8 +203,13 @@ functionaltest_sources = \
 	tests/functionaltests/test_autoping.c tests/functionaltests/test_autoping.h \
 	tests/functionaltests/test_disco.c tests/functionaltests/test_disco.h \
 	tests/functionaltests/test_export_import.c tests/functionaltests/test_export_import.h \
+	tests/functionaltests/test_ai.c tests/functionaltests/test_ai.h \
+	tests/functionaltests/ai_http_stub.c tests/functionaltests/ai_http_stub.h \
+	tests/functionaltests/test_ai_http.c tests/functionaltests/test_ai_http.h \
 	tests/functionaltests/functionaltests.c
 
+dist_check_DATA = tests/functionaltests/ai_http_stub.py
+
 main_source = src/main.c
 
 python_sources = \

src/ai/ai_client.c

@@ -1196,8 +1196,8 @@ _build_json_payload(AISession* session, const gchar* prompt)
     return json_payload;
 }
 
-static gchar*
+gchar*
-_parse_ai_response(const gchar* response_json)
+ai_parse_response(const gchar* response_json)
 {
     if (!response_json || strlen(response_json) == 0)
         return NULL;
@@ -1283,8 +1283,8 @@ _parse_ai_response(const gchar* response_json)
  * Extract error message from an API error JSON response.
  * Handles format: {"error":{"message":"...","type":"...","code":...}}
  */
-static gchar*
+gchar*
-_parse_error_response(const gchar* error_json)
+ai_parse_error_message(const gchar* error_json)
 {
     if (!error_json || strlen(error_json) == 0)
         return NULL;
@@ -1420,7 +1420,7 @@ _ai_request_thread(gpointer data)
         log_debug("[AI-THREAD] HTTP error response body (%zu bytes): %s",
                   response.size, response.data ? response.data : "NULL");
         /* Try to extract the actual error message from the JSON response */
-        auto_gchar gchar* parsed_error = _parse_error_response(response.data);
+        auto_gchar gchar* parsed_error = ai_parse_error_message(response.data);
         auto_gchar gchar* error_msg = parsed_error ? g_strdup_printf("HTTP %ld: %s", http_code, parsed_error) : g_strdup_printf("HTTP %ld: %s", http_code, response.data && strlen(response.data) > 0 ? response.data : "Unknown error");
         log_error("AI request failed for %s/%s: %s", session->provider_name, session->model, error_msg);
         _aiwin_display_error(user_data, error_msg);
@@ -1429,7 +1429,7 @@ _ai_request_thread(gpointer data)
         log_debug("[AI-THREAD] Raw API response (%zu bytes): %s", response.size, response.data ? response.data : "NULL");
         auto_gchar gchar* response_data = response.data;
         response.data = NULL;
-        auto_gchar gchar* content = _parse_ai_response(response_data);
+        auto_gchar gchar* content = ai_parse_response(response_data);
         if (content) {
             /* Add assistant response to history */
             ai_session_add_message(session, "assistant", content);

src/ai/ai_client.h

@@ -169,7 +169,7 @@ gboolean ai_fetch_models(const gchar* provider_name, gpointer user_data);
 gboolean ai_models_are_fresh(const gchar* provider_name);
 
 /* ========================================================================
- * Model Parsing (for testing)
+ * Parsing helpers (exposed for testing)
  * ======================================================================== */
 
 /**
@@ -180,6 +180,24 @@ gboolean ai_models_are_fresh(const gchar* provider_name);
  */
 void ai_parse_models_from_json(AIProvider* provider, const gchar* json);
 
+/**
+ * Extract assistant content from an LLM response body. Tries Perplexity
+ * /v1/responses "text" first, falls back to OpenAI "content". Decodes
+ * the \" and \n escape sequences only.
+ * @param response_json The JSON body from the provider
+ * @return Newly allocated content string, or NULL if not found (caller frees)
+ */
+gchar* ai_parse_response(const gchar* response_json);
+
+/**
+ * Extract human-readable error message from an API error envelope.
+ * Expected format: {"error":{"message":"...","type":"...","code":...}}
+ * Decodes \" \n \\ \t escapes.
+ * @param error_json The JSON body of the error response
+ * @return Newly allocated error message, or NULL if not parseable (caller frees)
+ */
+gchar* ai_parse_error_message(const gchar* error_json);
+
 /* ========================================================================
  * Session Management
  * ======================================================================== */

tests/functionaltests/ai_http_stub.c

@@ -0,0 +1,100 @@
+/*
+ * ai_http_stub.c
+ *
+ * Spawns tests/functionaltests/ai_http_stub.py as a child process for
+ * functional tests that exercise the AI client's HTTP code path. The
+ * stub listens on 127.0.0.1 on an OS-chosen port and prints "PORT=<n>"
+ * as its first line; we read it back and hand the port to the caller.
+ */
+
+#include "ai_http_stub.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#define STUB_SCRIPT "../tests/functionaltests/ai_http_stub.py"
+#define READLINE_MAX 64
+
+static pid_t stub_pid = 0;
+
+int
+ai_http_stub_start(const char* mode, const char* reply)
+{
+    int pipefd[2];
+    if (pipe(pipefd) != 0) {
+        return 0;
+    }
+
+    pid_t pid = fork();
+    if (pid < 0) {
+        close(pipefd[0]);
+        close(pipefd[1]);
+        return 0;
+    }
+
+    if (pid == 0) {
+        /* Child: redirect stdout to the pipe write end, then exec the stub. */
+        close(pipefd[0]);
+        dup2(pipefd[1], STDOUT_FILENO);
+        close(pipefd[1]);
+
+        if (mode) {
+            setenv("AI_STUB_MODE", mode, 1);
+        }
+        if (reply) {
+            setenv("AI_STUB_REPLY", reply, 1);
+        }
+        /* Argument "0" -> let the OS pick a free port. */
+        execlp("python3", "python3", STUB_SCRIPT, "0", (char*)NULL);
+        /* Falls through on exec failure. */
+        _exit(127);
+    }
+
+    /* Parent: read "PORT=<n>\n" from the child's stdout. */
+    close(pipefd[1]);
+
+    char buf[READLINE_MAX] = { 0 };
+    ssize_t total = 0;
+    while (total < (ssize_t)sizeof(buf) - 1) {
+        ssize_t n = read(pipefd[0], buf + total, sizeof(buf) - 1 - total);
+        if (n <= 0) {
+            break;
+        }
+        total += n;
+        if (memchr(buf, '\n', total)) {
+            break;
+        }
+    }
+    close(pipefd[0]);
+
+    int port = 0;
+    if (sscanf(buf, "PORT=%d", &port) != 1 || port <= 0) {
+        kill(pid, SIGTERM);
+        waitpid(pid, NULL, 0);
+        return 0;
+    }
+
+    stub_pid = pid;
+    return port;
+}
+
+void
+ai_http_stub_stop(void)
+{
+    if (stub_pid <= 0) {
+        return;
+    }
+    kill(stub_pid, SIGTERM);
+    /* Give the stub a moment to exit cleanly, then reap. */
+    int status = 0;
+    pid_t waited = waitpid(stub_pid, &status, 0);
+    (void)waited;
+    (void)status;
+    stub_pid = 0;
+}

tests/functionaltests/ai_http_stub.h

@@ -0,0 +1,25 @@
+#ifndef __H_AI_HTTP_STUB
+#define __H_AI_HTTP_STUB
+
+#include <sys/types.h>
+
+/*
+ * Spawn the Python AI stub script (tests/functionaltests/ai_http_stub.py).
+ *
+ * mode      — one of "ok", "openai", "401", "500", "models" (see the stub
+ *             script). Selects the response body and HTTP status.
+ * reply     — body text used by "ok"/"openai"/"401" modes. Pass NULL for
+ *             the default ("MOCK-REPLY").
+ *
+ * Returns the listening port (>0) on success, 0 on failure. The child's
+ * pid is recorded internally; call ai_http_stub_stop() to terminate it.
+ */
+int ai_http_stub_start(const char* mode, const char* reply);
+
+/*
+ * Send SIGTERM to the most recently spawned stub and reap it.
+ * No-op if no stub is running.
+ */
+void ai_http_stub_stop(void);
+
+#endif

tests/functionaltests/ai_http_stub.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python3
+"""
+Minimal HTTP stub for AI functional tests.
+
+Listens on 127.0.0.1:<port> and serves canned JSON responses for any POST.
+Behaviour is selected via the URL path and the AI_STUB_MODE environment
+variable, set by the test runner before exec().
+
+Modes:
+  - "ok"     : 200 with a valid OpenAI Responses-API body
+                ({"output":[{"content":[{"text":"...","type":"output_text"}]}]})
+  - "openai" : 200 with a legacy OpenAI Chat Completions body
+                ({"choices":[{"message":{"content":"..."}}]})
+  - "401"    : 401 with an OpenAI-style error envelope
+  - "500"    : 500 with a body that triggers the parse-error fallback
+  - "models" : 200 with a /v1/models list body
+
+The reply text is taken from AI_STUB_REPLY (default: "MOCK-REPLY").
+
+The stub writes its actual listening port to stdout as a single line
+"PORT=<n>" so the parent can read it back, then runs until SIGTERM.
+"""
+import json
+import os
+import sys
+from http.server import HTTPServer, BaseHTTPRequestHandler
+
+
+REPLY = os.environ.get("AI_STUB_REPLY", "MOCK-REPLY")
+MODE = os.environ.get("AI_STUB_MODE", "ok")
+
+
+def _dumps(body: object) -> bytes:
+    """Produce compact JSON without whitespace — profanity's hand-rolled
+    parser does strstr for `"key":"`, which fails when json.dumps inserts
+    a space after the colon by default."""
+    return json.dumps(body, separators=(",", ":")).encode("utf-8")
+
+
+def _body_for(mode: str) -> tuple[int, bytes]:
+    if mode == "ok":
+        body = {
+            "output": [
+                {
+                    "content": [
+                        {"text": REPLY, "type": "output_text"}
+                    ]
+                }
+            ]
+        }
+        return 200, _dumps(body)
+    if mode == "openai":
+        body = {
+            "choices": [
+                {"message": {"role": "assistant", "content": REPLY}}
+            ]
+        }
+        return 200, _dumps(body)
+    if mode == "401":
+        body = {
+            "error": {
+                "message": REPLY,
+                "type": "invalid_request_error",
+                "code": "invalid_api_key",
+            }
+        }
+        return 401, _dumps(body)
+    if mode == "500":
+        return 500, b"<html><body>Internal Server Error</body></html>"
+    if mode == "models":
+        body = {
+            "object": "list",
+            "data": [
+                {"id": "model-a", "object": "model"},
+                {"id": "model-b", "object": "model"},
+                {"id": "model-c", "object": "model"},
+            ],
+        }
+        return 200, _dumps(body)
+    return 200, b"{}"
+
+
+class StubHandler(BaseHTTPRequestHandler):
+    def _send(self):
+        status, body = _body_for(MODE)
+        self.send_response(status)
+        self.send_header("Content-Type", "application/json")
+        self.send_header("Content-Length", str(len(body)))
+        self.end_headers()
+        self.wfile.write(body)
+
+    def do_POST(self):
+        length = int(self.headers.get("Content-Length", 0))
+        if length:
+            self.rfile.read(length)
+        self._send()
+
+    def do_GET(self):
+        self._send()
+
+    def log_message(self, fmt, *args):
+        return
+
+
+def main() -> None:
+    port = int(sys.argv[1]) if len(sys.argv) > 1 else 0
+    srv = HTTPServer(("127.0.0.1", port), StubHandler)
+    actual = srv.server_address[1]
+    print(f"PORT={actual}", flush=True)
+    try:
+        srv.serve_forever()
+    except KeyboardInterrupt:
+        pass
+
+
+if __name__ == "__main__":
+    main()

tests/functionaltests/functionaltests.c

@@ -59,6 +59,8 @@
 #ifdef HAVE_SQLITE
 #include "test_export_import.h"
 #endif
+#include "test_ai.h"
+#include "test_ai_http.h"
 
 /* Macro to wrap each test with setup/teardown functions */
 #define PROF_FUNC_TEST(test)                                \
@@ -66,6 +68,14 @@
         #test, test, init_prof_test, close_prof_test, #test \
     }
 
+/* AI tests use a custom init that primes stabber via prof_connect so
+ * stbbr_stop() in close_prof_test() doesn't hang on a never-connected
+ * server thread. See ai_init_test() in test_ai.c. */
+#define PROF_FUNC_TEST_AI(test)                          \
+    {                                                    \
+        #test, test, ai_init_test, close_prof_test, #test \
+    }
+
 #ifdef HAVE_SQLITE
 /* Custom init that sets a non-UTC timezone (POSIX TST-3 = UTC+3) */
 static int
@@ -84,9 +94,9 @@ main(int argc, char* argv[])
     int group = 0; /* 0 = all groups */
     if (argc > 1) {
         group = atoi(argv[1]);
-        if (group < 1 || group > 4) {
+        if (group < 1 || group > 5) {
             fprintf(stderr, "Usage: %s [group]\n", argv[0]);
-            fprintf(stderr, "  group: 1-4 to run specific group, or omit for all\n");
+            fprintf(stderr, "  group: 1-5 to run specific group, or omit for all\n");
             return 1;
         }
     }
@@ -307,6 +317,39 @@ main(int argc, char* argv[])
 #endif
     };
 
+    /* ============================================================
+     * GROUP 5: AI command surface (console + HTTP stub)
+     * Standalone because AI tests don't use stabber's XMPP path; mixing
+     * them with XMPP-bound tests in the same group poisons stabber state
+     * between fixture init/teardown cycles and hangs subsequent
+     * prof_connect() calls.
+     * ============================================================ */
+    const struct CMUnitTest group5_tests[] = {
+        /* Tier A — no network calls */
+        PROF_FUNC_TEST_AI(ai_no_args_shows_help),
+        PROF_FUNC_TEST_AI(ai_providers_lists_defaults),
+        PROF_FUNC_TEST_AI(ai_providers_list_shows_key_status),
+        PROF_FUNC_TEST_AI(ai_set_provider_adds_custom),
+        PROF_FUNC_TEST_AI(ai_set_token_marks_key_set),
+        PROF_FUNC_TEST_AI(ai_start_unknown_provider_errors),
+        PROF_FUNC_TEST_AI(ai_start_without_key_errors),
+        PROF_FUNC_TEST_AI(ai_start_with_key_opens_window),
+        PROF_FUNC_TEST_AI(ai_clear_without_window_errors),
+        PROF_FUNC_TEST_AI(ai_remove_provider_works),
+        PROF_FUNC_TEST_AI(ai_remove_provider_unknown_errors),
+        PROF_FUNC_TEST_AI(ai_set_default_provider_unknown_errors),
+        PROF_FUNC_TEST_AI(ai_set_default_model_updates_provider),
+        PROF_FUNC_TEST_AI(ai_switch_without_window_errors),
+        PROF_FUNC_TEST_AI(ai_bad_subcommand_shows_usage),
+
+        /* Tier B — full request/response through Python HTTP stub */
+        PROF_FUNC_TEST_AI(ai_http_prompt_returns_ok),
+        PROF_FUNC_TEST_AI(ai_http_prompt_openai_format),
+        PROF_FUNC_TEST_AI(ai_http_prompt_401_shows_error),
+        PROF_FUNC_TEST_AI(ai_http_prompt_500_surfaced),
+        PROF_FUNC_TEST_AI(ai_http_models_fetch_lists_models),
+    };
+
     /* Test group registry for easy extension */
     struct
     {
@@ -318,6 +361,7 @@ main(int argc, char* argv[])
         { "Group 2: ExportImport/Receipts", group2_tests, ARRAY_SIZE(group2_tests) },
         { "Group 3: Presence/Disconnect/DBHistory/Message/MUC-DB", group3_tests, ARRAY_SIZE(group3_tests) },
         { "Group 4: Session/MUC/Carbons/MigrationStress", group4_tests, ARRAY_SIZE(group4_tests) },
+        { "Group 5: AI command surface (Tier A + Tier B)", group5_tests, ARRAY_SIZE(group5_tests) },
     };
     const int num_groups = ARRAY_SIZE(groups);
 

tests/functionaltests/proftest.c

@@ -20,7 +20,7 @@
 #include "proftest.h"
 
 /* Number of parallel test groups for CI builds */
-#define TEST_GROUPS 4
+#define TEST_GROUPS 5
 
 /* Number of ports reserved per test group; allows skipping TIME_WAIT ports */
 #define PORTS_PER_GROUP 50

tests/functionaltests/test_ai.c

@@ -0,0 +1,241 @@
+/*
+ * test_ai.c
+ *
+ * Functional tests for the /ai command surface (Tier A — no network).
+ *
+ * These tests interact with profanity through its PTY console and exercise
+ * paths that do not reach libcurl: command parsing, provider registration,
+ * key/setting/default storage, error messages, and AI window creation.
+ *
+ * Tests that require an actual provider HTTP exchange (prompt -> response,
+ * /ai models <provider>, HTTP error envelopes) are out of scope here and
+ * belong in a separate suite backed by a local HTTP stub.
+ */
+
+#include <glib.h>
+#include "prof_cmocka.h"
+#include <stdlib.h>
+#include <string.h>
+
+#include "proftest.h"
+#include "test_ai.h"
+
+int
+ai_init_test(void** state)
+{
+    int ret = init_prof_test(state);
+    if (ret != 0) {
+        return ret;
+    }
+    /* Connect to stabber even though AI tests don't use XMPP. Without this
+     * stabber's accept loop has no client to disconnect on /quit, and
+     * stbbr_stop() in close_prof_test() hangs uninterruptibly when joining
+     * the server thread. */
+    prof_connect();
+    return 0;
+}
+
+void
+ai_no_args_shows_help(void** state)
+{
+    /* `/ai` with no arguments lists the built-in providers and a usage hint. */
+    prof_input("/ai");
+
+    prof_timeout(5);
+    assert_true(prof_output_exact("AI Chat - OpenAI-compatible API client"));
+    assert_true(prof_output_exact("Configured providers:"));
+    assert_true(prof_output_regex("openai"));
+    assert_true(prof_output_regex("perplexity"));
+    assert_true(prof_output_regex("Use '/ai start' to begin a chat"));
+    prof_timeout_reset();
+}
+
+void
+ai_providers_lists_defaults(void** state)
+{
+    /* `/ai providers` (no "list") shows the built-in list with URLs. */
+    prof_input("/ai providers");
+
+    prof_timeout(5);
+    assert_true(prof_output_exact("Available AI providers:"));
+    assert_true(prof_output_regex("openai"));
+    assert_true(prof_output_regex("perplexity"));
+    prof_timeout_reset();
+}
+
+void
+ai_providers_list_shows_key_status(void** state)
+{
+    /* `/ai providers list` lists each configured provider with key status. */
+    prof_input("/ai providers list");
+
+    prof_timeout(5);
+    assert_true(prof_output_exact("Configured providers:"));
+    /* No tokens have been set yet in this fresh session. */
+    assert_true(prof_output_regex("Key: NOT configured"));
+    prof_timeout_reset();
+}
+
+void
+ai_set_provider_adds_custom(void** state)
+{
+    /* Adding a custom provider should make it appear in /ai providers list. */
+    prof_input("/ai set provider mock http://127.0.0.1:1/");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("Provider 'mock' configured"));
+    prof_timeout_reset();
+
+    prof_input("/ai providers list");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("mock"));
+    assert_true(prof_output_regex("http://127.0.0.1:1/"));
+    prof_timeout_reset();
+}
+
+void
+ai_set_token_marks_key_set(void** state)
+{
+    /* Setting a token must flip the provider's key status to "configured". */
+    prof_input("/ai set token openai sk-fake-test-key");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("API token set for provider: openai"));
+    prof_timeout_reset();
+
+    prof_input("/ai providers list");
+
+    prof_timeout(5);
+    /* openai now shows "Key: configured" while perplexity stays unconfigured. */
+    assert_true(prof_output_regex("Key: configured"));
+    prof_timeout_reset();
+}
+
+void
+ai_start_unknown_provider_errors(void** state)
+{
+    /* Unknown provider name should error out without creating a window. */
+    prof_input("/ai start nope_provider somemodel");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("Provider 'nope_provider' not found"));
+    prof_timeout_reset();
+}
+
+void
+ai_start_without_key_errors(void** state)
+{
+    /* Known provider without an API key should refuse to start. */
+    prof_input("/ai start openai gpt-4");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("No API key set for provider 'openai'"));
+    prof_timeout_reset();
+}
+
+void
+ai_start_with_key_opens_window(void** state)
+{
+    /* With a token set, /ai start should create a WIN_AI window. */
+    prof_input("/ai set token openai sk-fake-test-key");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("API token set for provider: openai"));
+    prof_timeout_reset();
+
+    prof_input("/ai start openai gpt-4");
+
+    prof_timeout(5);
+    /* /ai start switches focus to the new WIN_AI window; cons_show output
+     * to the console is therefore not the right place to look. The window
+     * itself prints "AI Chat: <provider>/<model>" as its first line. */
+    assert_true(prof_output_regex("AI Chat: openai/gpt-4"));
+    prof_timeout_reset();
+}
+
+void
+ai_clear_without_window_errors(void** state)
+{
+    /* /ai clear from the console (no active AI window) should report nicely. */
+    prof_input("/ai clear");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("No active AI chat window to clear"));
+    prof_timeout_reset();
+}
+
+void
+ai_remove_provider_works(void** state)
+{
+    /* Round-trip: add -> verify present -> remove -> verify gone. */
+    prof_input("/ai set provider tmpprov http://127.0.0.1:2/");
+    prof_timeout(5);
+    assert_true(prof_output_regex("Provider 'tmpprov' configured"));
+    prof_timeout_reset();
+
+    prof_input("/ai remove provider tmpprov");
+    prof_timeout(5);
+    assert_true(prof_output_regex("Provider 'tmpprov' removed"));
+    prof_timeout_reset();
+
+    prof_input("/ai remove provider tmpprov");
+    prof_timeout(5);
+    assert_true(prof_output_regex("Provider 'tmpprov' not found"));
+    prof_timeout_reset();
+}
+
+void
+ai_remove_provider_unknown_errors(void** state)
+{
+    /* Removing a provider that was never added must report "not found". */
+    prof_input("/ai remove provider nonexistent_xyz");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("Provider 'nonexistent_xyz' not found"));
+    prof_timeout_reset();
+}
+
+void
+ai_set_default_provider_unknown_errors(void** state)
+{
+    /* Setting an unknown default provider should error, not silently accept. */
+    prof_input("/ai set default-provider does_not_exist");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("Provider 'does_not_exist' not found"));
+    prof_timeout_reset();
+}
+
+void
+ai_set_default_model_updates_provider(void** state)
+{
+    /* Setting a default model is acknowledged on the console. */
+    prof_input("/ai set default-model openai gpt-5-preview");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("Default model for provider 'openai' set to: gpt-5-preview"));
+    prof_timeout_reset();
+}
+
+void
+ai_switch_without_window_errors(void** state)
+{   
+    /* /ai switch with no active AI window should produce an actionable error. */
+    prof_input("/ai switch openai gpt-4");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("No active AI chat window"));
+    prof_timeout_reset();
+}
+
+void
+ai_bad_subcommand_shows_usage(void** state)
+{
+    /* An unknown /ai subcommand should fall through to cons_bad_cmd_usage. */
+    prof_input("/ai not_a_subcommand");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("Invalid usage, see '/help ai'"));
+    prof_timeout_reset();
+}

tests/functionaltests/test_ai.h

@@ -0,0 +1,28 @@
+#ifndef __H_FUNC_TEST_AI
+#define __H_FUNC_TEST_AI
+
+/*
+ * AI tests don't exercise the XMPP path, but the test fixture's
+ * stbbr_stop() hangs indefinitely when no client ever connected to
+ * stabber. ai_init_test wraps init_prof_test with a prof_connect()
+ * so stabber sees a graceful disconnect at teardown.
+ */
+int ai_init_test(void** state);
+
+void ai_no_args_shows_help(void** state);
+void ai_providers_lists_defaults(void** state);
+void ai_providers_list_shows_key_status(void** state);
+void ai_set_provider_adds_custom(void** state);
+void ai_set_token_marks_key_set(void** state);
+void ai_start_unknown_provider_errors(void** state);
+void ai_start_without_key_errors(void** state);
+void ai_start_with_key_opens_window(void** state);
+void ai_clear_without_window_errors(void** state);
+void ai_remove_provider_works(void** state);
+void ai_remove_provider_unknown_errors(void** state);
+void ai_set_default_provider_unknown_errors(void** state);
+void ai_set_default_model_updates_provider(void** state);
+void ai_switch_without_window_errors(void** state);
+void ai_bad_subcommand_shows_usage(void** state);
+
+#endif

tests/functionaltests/test_ai_http.c

@@ -0,0 +1,157 @@
+/*
+ * test_ai_http.c
+ *
+ * Functional tests for the /ai command surface that exercise the libcurl
+ * HTTP code path. A small Python HTTP stub (ai_http_stub.py) is spawned
+ * per-test on a free local port; profanity is configured to point at it
+ * via `/ai set provider`. The stub serves canned JSON whose shape is
+ * controlled via AI_STUB_MODE.
+ *
+ * These tests intentionally do not race the worker thread directly —
+ * they rely on prof_timeout() retries to catch the response once it
+ * propagates back through the AI window.
+ */
+
+#include <glib.h>
+#include "prof_cmocka.h"
+#include <stdlib.h>
+#include <string.h>
+
+#include "proftest.h"
+#include "ai_http_stub.h"
+
+#define WAIT_AI_RESPONSE_SEC 10
+
+/*
+ * Configure profanity to use the spawned stub as a provider named "mock"
+ * with a dummy bearer token, then issue /ai start to open the AI window.
+ * Returns the stub port on success, fails the test on stub-spawn failure.
+ */
+static int
+_setup_mock_provider(const char* mode, const char* reply)
+{
+    int port = ai_http_stub_start(mode, reply);
+    assert_int_not_equal(0, port);
+
+    char cmd[256];
+    g_snprintf(cmd, sizeof(cmd), "/ai set provider mock http://127.0.0.1:%d/", port);
+    prof_input(cmd);
+    prof_timeout(5);
+    assert_true(prof_output_regex("Provider 'mock' configured"));
+    prof_timeout_reset();
+
+    prof_input("/ai set token mock fake-test-token");
+    prof_timeout(5);
+    assert_true(prof_output_regex("API token set for provider: mock"));
+    prof_timeout_reset();
+
+    return port;
+}
+
+void
+ai_http_prompt_returns_ok(void** state)
+{
+    /* Happy path: stub returns Responses API "text" body; reply appears in window. */
+    _setup_mock_provider("ok", "STUB-HELLO");
+
+    prof_input("/ai start mock testmodel");
+    prof_timeout(5);
+    assert_true(prof_output_regex("AI Chat: mock/testmodel"));
+    prof_timeout_reset();
+
+    /* Plain text in AI window goes through cl_ev_send_ai_msg -> ai_send_prompt. */
+    prof_input("hello stub");
+
+    prof_timeout(WAIT_AI_RESPONSE_SEC);
+    assert_true(prof_output_regex("STUB-HELLO"));
+    prof_timeout_reset();
+
+    ai_http_stub_stop();
+}
+
+void
+ai_http_prompt_openai_format(void** state)
+{
+    /* Legacy OpenAI chat completions shape: "choices[].message.content". */
+    _setup_mock_provider("openai", "FROM-CHOICES");
+
+    prof_input("/ai start mock m");
+    prof_timeout(5);
+    assert_true(prof_output_regex("AI Chat: mock/m"));
+    prof_timeout_reset();
+
+    prof_input("anything");
+
+    prof_timeout(WAIT_AI_RESPONSE_SEC);
+    assert_true(prof_output_regex("FROM-CHOICES"));
+    prof_timeout_reset();
+
+    ai_http_stub_stop();
+}
+
+void
+ai_http_prompt_401_shows_error(void** state)
+{
+    /* 401 with an OpenAI-style error envelope.
+     * ai_parse_error_message() should extract the inner message; the AI
+     * window then displays "HTTP 401: <message>". */
+    _setup_mock_provider("401", "Bad token, try another");
+
+    prof_input("/ai start mock m");
+    prof_timeout(5);
+    assert_true(prof_output_regex("AI Chat: mock/m"));
+    prof_timeout_reset();
+
+    prof_input("prompt");
+
+    prof_timeout(WAIT_AI_RESPONSE_SEC);
+    /* Either the parsed message surfaces, or the raw HTTP 401 envelope. */
+    assert_true(prof_output_regex("HTTP 401") && prof_output_regex("Bad token, try another"));
+    prof_timeout_reset();
+
+    ai_http_stub_stop();
+}
+
+void
+ai_http_prompt_500_surfaced(void** state)
+{
+    /* 500 with a non-JSON HTML body. Parser falls back to raw body in HTTP error. */
+    _setup_mock_provider("500", NULL);
+
+    prof_input("/ai start mock m");
+    prof_timeout(5);
+    assert_true(prof_output_regex("AI Chat: mock/m"));
+    prof_timeout_reset();
+
+    prof_input("trigger");
+
+    prof_timeout(WAIT_AI_RESPONSE_SEC);
+    assert_true(prof_output_regex("HTTP 500"));
+    prof_timeout_reset();
+
+    ai_http_stub_stop();
+}
+
+void
+ai_http_models_fetch_lists_models(void** state)
+{
+    /* /v1/models endpoint returns a list of three models. /ai models <p>
+     * caches them silently; /ai models <p> --cached then displays the names. */
+    _setup_mock_provider("models", NULL);
+
+    prof_input("/ai models mock");
+
+    prof_timeout(WAIT_AI_RESPONSE_SEC);
+    assert_true(prof_output_regex("Cached 3 models for provider 'mock'"));
+    prof_timeout_reset();
+
+    prof_input("/ai models mock --cached");
+
+    prof_timeout(5);
+    assert_true(prof_output_regex("model-a"));
+    assert_true(prof_output_regex("model-b"));
+    assert_true(prof_output_regex("model-c"));
+    prof_timeout_reset();
+
+    ai_http_stub_stop();
+}

tests/functionaltests/test_ai_http.h

@@ -0,0 +1,10 @@
+#ifndef __H_FUNC_TEST_AI_HTTP
+#define __H_FUNC_TEST_AI_HTTP
+
+void ai_http_prompt_returns_ok(void** state);
+void ai_http_prompt_openai_format(void** state);
+void ai_http_prompt_401_shows_error(void** state);
+void ai_http_prompt_500_surfaced(void** state);
+void ai_http_models_fetch_lists_models(void** state);
+
+#endif

tests/unittests/test_ai_client.c

@@ -1,7 +1,10 @@
 #include "prof_cmocka.h"
 #include "common.h"
 #include "ai/ai_client.h"
+#include "config/preferences.h"
+#include "helpers.h"
 #include <stdlib.h>
+#include <string.h>
 
 /* ========================================================================
  * Setup/Teardown
@@ -867,3 +870,598 @@ test_ai_parse_models_with_whitespace(void** state)
     ai_provider_unref(provider);
     ai_client_shutdown();
 }
+
+/* ========================================================================
+ * Setup combining prefs + ai_client for round-trip persistence tests
+ * ======================================================================== */
+
+int
+ai_client_setup_with_prefs(void** state)
+{
+    if (load_preferences(state) != 0) {
+        return 1;
+    }
+    ai_client_init();
+    return 0;
+}
+
+int
+ai_client_teardown_with_prefs(void** state)
+{
+    ai_client_shutdown();
+    close_preferences(state);
+    return 0;
+}
+
+/* ========================================================================
+ * Chat response parser tests (ai_parse_response)
+ * ======================================================================== */
+
+void
+test_ai_parse_response_openai_content(void** state)
+{
+    const gchar* json = "{\"choices\":[{\"message\":{\"role\":\"assistant\",\"content\":\"Hello, world!\"}}]}";
+    auto_gchar gchar* out = ai_parse_response(json);
+    assert_non_null(out);
+    assert_string_equal("Hello, world!", out);
+}
+
+void
+test_ai_parse_response_perplexity_text(void** state)
+{
+    const gchar* json = "{\"output\":[{\"content\":[{\"text\":\"Search result\",\"type\":\"output_text\"}]}]}";
+    auto_gchar gchar* out = ai_parse_response(json);
+    assert_non_null(out);
+    assert_string_equal("Search result", out);
+}
+
+void
+test_ai_parse_response_text_preferred_over_content(void** state)
+{
+    /* When both formats are present, "text" wins (Perplexity path tried first). */
+    const gchar* json = "{\"text\":\"from text field\",\"content\":\"from content field\"}";
+    auto_gchar gchar* out = ai_parse_response(json);
+    assert_non_null(out);
+    assert_string_equal("from text field", out);
+}
+
+void
+test_ai_parse_response_escaped_quote(void** state)
+{
+    const gchar* json = "{\"content\":\"He said \\\"hello\\\" today\"}";
+    auto_gchar gchar* out = ai_parse_response(json);
+    assert_non_null(out);
+    assert_string_equal("He said \"hello\" today", out);
+}
+
+void
+test_ai_parse_response_newline_escape(void** state)
+{
+    const gchar* json = "{\"content\":\"line one\\nline two\"}";
+    auto_gchar gchar* out = ai_parse_response(json);
+    assert_non_null(out);
+    assert_string_equal("line one\nline two", out);
+}
+
+void
+test_ai_parse_response_empty_content(void** state)
+{
+    const gchar* json = "{\"content\":\"\"}";
+    auto_gchar gchar* out = ai_parse_response(json);
+    assert_non_null(out);
+    assert_string_equal("", out);
+}
+
+void
+test_ai_parse_response_missing_field(void** state)
+{
+    const gchar* json = "{\"foo\":\"bar\"}";
+    gchar* out = ai_parse_response(json);
+    assert_null(out);
+}
+
+void
+test_ai_parse_response_null_input(void** state)
+{
+    assert_null(ai_parse_response(NULL));
+}
+
+void
+test_ai_parse_response_empty_input(void** state)
+{
+    assert_null(ai_parse_response(""));
+}
+
+void
+test_ai_parse_response_percent_signs_safe(void** state)
+{
+    /* Format-string safety: %s, %d in content must not be interpreted later. */
+    const gchar* json = "{\"content\":\"100% done with %s and %d markers\"}";
+    auto_gchar gchar* out = ai_parse_response(json);
+    assert_non_null(out);
+    assert_string_equal("100% done with %s and %d markers", out);
+}
+
+void
+test_ai_parse_response_braces_in_content(void** state)
+{
+    /* Content containing JSON-looking braces should not confuse the parser. */
+    const gchar* json = "{\"content\":\"use {key: value} syntax\"}";
+    auto_gchar gchar* out = ai_parse_response(json);
+    assert_non_null(out);
+    assert_string_equal("use {key: value} syntax", out);
+}
+
+void
+test_ai_parse_response_multiline_content(void** state)
+{
+    const gchar* json = "{\"content\":\"para 1\\n\\npara 2\\nlast\"}";
+    auto_gchar gchar* out = ai_parse_response(json);
+    assert_non_null(out);
+    assert_string_equal("para 1\n\npara 2\nlast", out);
+}
+
+/* ========================================================================
+ * Error response parser tests (ai_parse_error_message)
+ * ======================================================================== */
+
+void
+test_ai_parse_error_standard_envelope(void** state)
+{
+    const gchar* json = "{\"error\":{\"message\":\"Invalid API key provided\",\"type\":\"invalid_request_error\",\"code\":\"invalid_api_key\"}}";
+    auto_gchar gchar* out = ai_parse_error_message(json);
+    assert_non_null(out);
+    assert_string_equal("Invalid API key provided", out);
+}
+
+void
+test_ai_parse_error_with_escapes(void** state)
+{
+    const gchar* json = "{\"error\":{\"message\":\"Field \\\"model\\\" is required\"}}";
+    auto_gchar gchar* out = ai_parse_error_message(json);
+    assert_non_null(out);
+    assert_string_equal("Field \"model\" is required", out);
+}
+
+void
+test_ai_parse_error_no_error_field(void** state)
+{
+    const gchar* json = "{\"message\":\"this is not in an error envelope\"}";
+    gchar* out = ai_parse_error_message(json);
+    assert_null(out);
+}
+
+void
+test_ai_parse_error_no_message_field(void** state)
+{
+    const gchar* json = "{\"error\":{\"type\":\"some_error\",\"code\":42}}";
+    gchar* out = ai_parse_error_message(json);
+    assert_null(out);
+}
+
+void
+test_ai_parse_error_null_input(void** state)
+{
+    assert_null(ai_parse_error_message(NULL));
+}
+
+void
+test_ai_parse_error_empty_input(void** state)
+{
+    assert_null(ai_parse_error_message(""));
+}
+
+void
+test_ai_parse_error_tab_escape(void** state)
+{
+    const gchar* json = "{\"error\":{\"message\":\"col1\\tcol2\"}}";
+    auto_gchar gchar* out = ai_parse_error_message(json);
+    assert_non_null(out);
+    assert_string_equal("col1\tcol2", out);
+}
+
+void
+test_ai_parse_error_backslash_escape(void** state)
+{
+    const gchar* json = "{\"error\":{\"message\":\"path C:\\\\Users\\\\x\"}}";
+    auto_gchar gchar* out = ai_parse_error_message(json);
+    assert_non_null(out);
+    assert_string_equal("path C:\\Users\\x", out);
+}
+
+/* ========================================================================
+ * Extended JSON escape tests
+ * ======================================================================== */
+
+void
+test_ai_json_escape_backspace(void** state)
+{
+    auto_gchar gchar* out = ai_json_escape("a\bb");
+    assert_string_equal("a\\bb", out);
+}
+
+void
+test_ai_json_escape_formfeed(void** state)
+{
+    auto_gchar gchar* out = ai_json_escape("a\fb");
+    assert_string_equal("a\\fb", out);
+}
+
+void
+test_ai_json_escape_carriage_return(void** state)
+{
+    auto_gchar gchar* out = ai_json_escape("a\rb");
+    assert_string_equal("a\\rb", out);
+}
+
+void
+test_ai_json_escape_all_specials_combined(void** state)
+{
+    auto_gchar gchar* out = ai_json_escape("\"\\/\b\f\n\r\t");
+    /* `/` is not escaped by the encoder (valid JSON either way). */
+    assert_string_equal("\\\"\\\\/\\b\\f\\n\\r\\t", out);
+}
+
+void
+test_ai_json_escape_passes_utf8_through(void** state)
+{
+    /* UTF-8 bytes are valid in JSON strings and should pass through unchanged. */
+    auto_gchar gchar* out = ai_json_escape("Привет 🦀");
+    assert_string_equal("Привет 🦀", out);
+}
+
+/* ========================================================================
+ * Autocomplete cycling with many providers
+ * ======================================================================== */
+
+void
+test_ai_providers_find_cycles_through_many(void** state)
+{
+    /* Add several providers sharing a prefix; cycling should visit each. */
+    ai_add_provider("alpha", "https://a.example/", NULL);
+    ai_add_provider("beta", "https://b.example/", NULL);
+    ai_add_provider("alphabet", "https://ab.example/", NULL);
+    ai_add_provider("alpine", "https://al.example/", NULL);
+
+    /* Three providers share prefix "alp": alpha, alphabet, alpine. */
+    GHashTable* seen = g_hash_table_new(g_str_hash, g_str_equal);
+
+    for (int i = 0; i < 3; i++) {
+        auto_gchar gchar* match = ai_providers_find("alp", FALSE, NULL);
+        assert_non_null(match);
+        /* Each call should return a result that starts with "alp". */
+        assert_true(g_str_has_prefix(match, "alp"));
+        g_hash_table_add(seen, g_strdup(match));
+    }
+
+    /* All three should have been seen (deterministic cycling). */
+    assert_int_equal(3, g_hash_table_size(seen));
+
+    g_hash_table_destroy(seen);
+}
+
+void
+test_ai_providers_find_previous_walks_backwards(void** state)
+{
+    ai_add_provider("alpha", "https://a/", NULL);
+    ai_add_provider("alphabet", "https://ab/", NULL);
+    ai_add_provider("alpine", "https://al/", NULL);
+
+    /* Forward then backward should yield matches with the shared prefix. */
+    auto_gchar gchar* forward = ai_providers_find("alp", FALSE, NULL);
+    auto_gchar gchar* back = ai_providers_find("alp", TRUE, NULL);
+
+    assert_non_null(forward);
+    assert_non_null(back);
+    assert_true(g_str_has_prefix(forward, "alp"));
+    assert_true(g_str_has_prefix(back, "alp"));
+}
+
+void
+test_ai_providers_find_wraps_around(void** state)
+{
+    ai_add_provider("alpha", "https://a/", NULL);
+    ai_add_provider("alphabet", "https://ab/", NULL);
+
+    /* Two matches; four forward calls should produce a repeat. */
+    auto_gchar gchar* r1 = ai_providers_find("alp", FALSE, NULL);
+    auto_gchar gchar* r2 = ai_providers_find("alp", FALSE, NULL);
+    auto_gchar gchar* r3 = ai_providers_find("alp", FALSE, NULL);
+    auto_gchar gchar* r4 = ai_providers_find("alp", FALSE, NULL);
+
+    assert_non_null(r1);
+    assert_non_null(r2);
+    assert_non_null(r3);
+    assert_non_null(r4);
+
+    /* The cycle of 2 must repeat: r1 == r3 and r2 == r4 (in some order). */
+    assert_int_equal(0, g_strcmp0(r1, r3));
+    assert_int_equal(0, g_strcmp0(r2, r4));
+    assert_int_not_equal(0, g_strcmp0(r1, r2));
+}
+
+/* ========================================================================
+ * Session edge cases
+ * ======================================================================== */
+
+void
+test_ai_session_add_message_null_session_no_crash(void** state)
+{
+    /* Should silently no-op rather than dereference NULL. */
+    ai_session_add_message(NULL, "user", "hello");
+}
+
+void
+test_ai_session_add_message_null_role_no_crash(void** state)
+{
+    AISession* s = ai_session_create("openai", "gpt-4");
+    assert_non_null(s);
+    ai_session_add_message(s, NULL, "content");
+    assert_int_equal(0, g_list_length(s->history));
+    ai_session_unref(s);
+}
+
+void
+test_ai_session_add_message_null_content_no_crash(void** state)
+{
+    AISession* s = ai_session_create("openai", "gpt-4");
+    assert_non_null(s);
+    ai_session_add_message(s, "user", NULL);
+    assert_int_equal(0, g_list_length(s->history));
+    ai_session_unref(s);
+}
+
+void
+test_ai_session_history_preserves_large_order(void** state)
+{
+    AISession* s = ai_session_create("openai", "gpt-4");
+    assert_non_null(s);
+
+    for (int i = 0; i < 100; i++) {
+        auto_gchar gchar* content = g_strdup_printf("msg-%d", i);
+        ai_session_add_message(s, (i % 2 == 0) ? "user" : "assistant", content);
+    }
+
+    assert_int_equal(100, g_list_length(s->history));
+
+    GList* curr = s->history;
+    for (int i = 0; i < 100 && curr; i++, curr = g_list_next(curr)) {
+        AIMessage* msg = curr->data;
+        auto_gchar gchar* expected = g_strdup_printf("msg-%d", i);
+        assert_string_equal(expected, msg->content);
+        assert_string_equal((i % 2 == 0) ? "user" : "assistant", msg->role);
+    }
+
+    ai_session_unref(s);
+}
+
+void
+test_ai_session_clear_empty_history(void** state)
+{
+    AISession* s = ai_session_create("openai", "gpt-4");
+    assert_non_null(s);
+    ai_session_clear_history(s);
+    assert_int_equal(0, g_list_length(s->history));
+    ai_session_unref(s);
+}
+
+void
+test_ai_session_set_model_null_keeps_old(void** state)
+{
+    AISession* s = ai_session_create("openai", "gpt-4");
+    assert_non_null(s);
+    ai_session_set_model(s, NULL);
+    assert_string_equal("gpt-4", s->model);
+    ai_session_unref(s);
+}
+
+void
+test_ai_session_unref_null_no_crash(void** state)
+{
+    ai_session_unref(NULL);
+}
+
+void
+test_ai_session_ref_null_returns_null(void** state)
+{
+    assert_null(ai_session_ref(NULL));
+}
+
+/* ========================================================================
+ * Provider edge cases
+ * ======================================================================== */
+
+void
+test_ai_get_provider_null_returns_null(void** state)
+{
+    assert_null(ai_get_provider(NULL));
+}
+
+void
+test_ai_remove_provider_null_returns_false(void** state)
+{
+    assert_false(ai_remove_provider(NULL));
+}
+
+void
+test_ai_remove_provider_twice_second_fails(void** state)
+{
+    ai_add_provider("once", "https://once/", NULL);
+    assert_true(ai_remove_provider("once"));
+    assert_false(ai_remove_provider("once"));
+}
+
+void
+test_ai_provider_survives_via_session_after_removal(void** state)
+{
+    ai_add_provider("temp_prov", "https://temp/", NULL);
+    ai_set_provider_key("temp_prov", "test-key");
+
+    AISession* s = ai_session_create("temp_prov", "model-x");
+    assert_non_null(s);
+
+    /* Remove from registry while session holds a ref. */
+    assert_true(ai_remove_provider("temp_prov"));
+    assert_null(ai_get_provider("temp_prov"));
+
+    /* Session's provider pointer must still be valid. */
+    assert_non_null(s->provider);
+    assert_string_equal("temp_prov", s->provider->name);
+    assert_string_equal("https://temp/", s->provider->api_url);
+
+    ai_session_unref(s);
+}
+
+/* ========================================================================
+ * Settings edge cases
+ * ======================================================================== */
+
+void
+test_ai_settings_multiple_keys_independent(void** state)
+{
+    ai_set_provider_setting("openai", "tools", "enabled");
+    ai_set_provider_setting("openai", "search", "disabled");
+
+    auto_gchar gchar* tools = ai_get_provider_setting("openai", "tools");
+    auto_gchar gchar* search = ai_get_provider_setting("openai", "search");
+
+    assert_string_equal("enabled", tools);
+    assert_string_equal("disabled", search);
+}
+
+void
+test_ai_settings_get_missing_returns_null(void** state)
+{
+    gchar* nope = ai_get_provider_setting("openai", "not_set");
+    assert_null(nope);
+}
+
+void
+test_ai_settings_isolated_between_providers(void** state)
+{
+    ai_set_provider_setting("openai", "tools", "yes");
+    ai_set_provider_setting("perplexity", "tools", "no");
+
+    auto_gchar gchar* a = ai_get_provider_setting("openai", "tools");
+    auto_gchar gchar* b = ai_get_provider_setting("perplexity", "tools");
+
+    assert_string_equal("yes", a);
+    assert_string_equal("no", b);
+}
+
+/* ========================================================================
+ * Model parsing edge cases
+ * ======================================================================== */
+
+void
+test_ai_parse_models_data_not_array(void** state)
+{
+    AIProvider* p = ai_add_provider("p1", "https://p/", NULL);
+    assert_non_null(p);
+
+    /* "data" present but not an array — parser should bail without crashing. */
+    const gchar* json = "{\"data\":\"not-an-array\"}";
+    ai_parse_models_from_json(p, json);
+
+    assert_int_equal(0, g_list_length(p->models));
+}
+
+void
+test_ai_parse_models_empty_data_array(void** state)
+{
+    AIProvider* p = ai_add_provider("p1", "https://p/", NULL);
+    assert_non_null(p);
+
+    const gchar* json = "{\"object\":\"list\",\"data\":[]}";
+    ai_parse_models_from_json(p, json);
+
+    assert_int_equal(0, g_list_length(p->models));
+}
+
+void
+test_ai_parse_models_id_outside_data_ignored(void** state)
+{
+    AIProvider* p = ai_add_provider("p1", "https://p/", NULL);
+    assert_non_null(p);
+
+    /* "id" outside a data-array object must not be picked up. */
+    const gchar* json = "{\"request_id\":\"req-123\",\"data\":[]}";
+    ai_parse_models_from_json(p, json);
+
+    assert_int_equal(0, g_list_length(p->models));
+}
+
+void
+test_ai_parse_models_multiple_models(void** state)
+{
+    AIProvider* p = ai_add_provider("p1", "https://p/", NULL);
+    assert_non_null(p);
+
+    const gchar* json = "{\"object\":\"list\",\"data\":["
+                        "{\"id\":\"m-1\",\"object\":\"model\"},"
+                        "{\"id\":\"m-2\",\"object\":\"model\"},"
+                        "{\"id\":\"m-3\",\"object\":\"model\"}"
+                        "]}";
+    ai_parse_models_from_json(p, json);
+
+    assert_int_equal(3, g_list_length(p->models));
+}
+
+/* ========================================================================
+ * Prefs round-trip tests
+ *
+ * These use ai_client_setup_with_prefs which initializes prefs first.
+ * ai_set_provider_key writes through to prefs_ai_set_token which then
+ * calls _save_prefs(); a subsequent shutdown+init should reload the key.
+ * ======================================================================== */
+
+void
+test_ai_prefs_round_trip_api_key(void** state)
+{
+    ai_set_provider_key("openai", "sk-persisted-123");
+
+    {
+        auto_gchar gchar* before = ai_get_provider_key("openai");
+        assert_non_null(before);
+        assert_string_equal("sk-persisted-123", before);
+    }
+
+    /* Cycle the AI client; prefs stay loaded across this. */
+    ai_client_shutdown();
+    ai_client_init();
+
+    auto_gchar gchar* after = ai_get_provider_key("openai");
+    assert_non_null(after);
+    assert_string_equal("sk-persisted-123", after);
+}
+
+void
+test_ai_prefs_round_trip_remove_key(void** state)
+{
+    ai_set_provider_key("openai", "sk-to-be-removed");
+    ai_set_provider_key("openai", NULL);
+
+    ai_client_shutdown();
+    ai_client_init();
+
+    auto_gchar gchar* after = ai_get_provider_key("openai");
+    assert_null(after);
+}
+
+void
+test_ai_prefs_multiple_providers_persist(void** state)
+{
+    ai_set_provider_key("openai", "sk-openai-key");
+    ai_set_provider_key("perplexity", "pplx-key");
+
+    ai_client_shutdown();
+    ai_client_init();
+
+    auto_gchar gchar* k1 = ai_get_provider_key("openai");
+    auto_gchar gchar* k2 = ai_get_provider_key("perplexity");
+
+    assert_non_null(k1);
+    assert_non_null(k2);
+    assert_string_equal("sk-openai-key", k1);
+    assert_string_equal("pplx-key", k2);
+}

tests/unittests/test_ai_client.h

@@ -60,3 +60,75 @@ void test_ai_start_provider_autocomplete_only_on_exact(void** state);
 void test_ai_models_find_null_session(void** state);
 void test_ai_models_find_null_provider(void** state);
 void test_ai_providers_find_cycling(void** state);
+
+/* Setup that also initializes prefs for round-trip persistence tests. */
+int ai_client_setup_with_prefs(void** state);
+int ai_client_teardown_with_prefs(void** state);
+
+/* Chat response parser tests (ai_parse_response) */
+void test_ai_parse_response_openai_content(void** state);
+void test_ai_parse_response_perplexity_text(void** state);
+void test_ai_parse_response_text_preferred_over_content(void** state);
+void test_ai_parse_response_escaped_quote(void** state);
+void test_ai_parse_response_newline_escape(void** state);
+void test_ai_parse_response_empty_content(void** state);
+void test_ai_parse_response_missing_field(void** state);
+void test_ai_parse_response_null_input(void** state);
+void test_ai_parse_response_empty_input(void** state);
+void test_ai_parse_response_percent_signs_safe(void** state);
+void test_ai_parse_response_braces_in_content(void** state);
+void test_ai_parse_response_multiline_content(void** state);
+
+/* Error response parser tests (ai_parse_error_message) */
+void test_ai_parse_error_standard_envelope(void** state);
+void test_ai_parse_error_with_escapes(void** state);
+void test_ai_parse_error_no_error_field(void** state);
+void test_ai_parse_error_no_message_field(void** state);
+void test_ai_parse_error_null_input(void** state);
+void test_ai_parse_error_empty_input(void** state);
+void test_ai_parse_error_tab_escape(void** state);
+void test_ai_parse_error_backslash_escape(void** state);
+
+/* Extended JSON escape tests */
+void test_ai_json_escape_backspace(void** state);
+void test_ai_json_escape_formfeed(void** state);
+void test_ai_json_escape_carriage_return(void** state);
+void test_ai_json_escape_all_specials_combined(void** state);
+void test_ai_json_escape_passes_utf8_through(void** state);
+
+/* Autocomplete cycling with many providers */
+void test_ai_providers_find_cycles_through_many(void** state);
+void test_ai_providers_find_previous_walks_backwards(void** state);
+void test_ai_providers_find_wraps_around(void** state);
+
+/* Session edge cases */
+void test_ai_session_add_message_null_session_no_crash(void** state);
+void test_ai_session_add_message_null_role_no_crash(void** state);
+void test_ai_session_add_message_null_content_no_crash(void** state);
+void test_ai_session_history_preserves_large_order(void** state);
+void test_ai_session_clear_empty_history(void** state);
+void test_ai_session_set_model_null_keeps_old(void** state);
+void test_ai_session_unref_null_no_crash(void** state);
+void test_ai_session_ref_null_returns_null(void** state);
+
+/* Provider edge cases */
+void test_ai_get_provider_null_returns_null(void** state);
+void test_ai_remove_provider_null_returns_false(void** state);
+void test_ai_remove_provider_twice_second_fails(void** state);
+void test_ai_provider_survives_via_session_after_removal(void** state);
+
+/* Settings edge cases */
+void test_ai_settings_multiple_keys_independent(void** state);
+void test_ai_settings_get_missing_returns_null(void** state);
+void test_ai_settings_isolated_between_providers(void** state);
+
+/* Model parsing edge cases */
+void test_ai_parse_models_data_not_array(void** state);
+void test_ai_parse_models_empty_data_array(void** state);
+void test_ai_parse_models_id_outside_data_ignored(void** state);
+void test_ai_parse_models_multiple_models(void** state);
+
+/* Prefs round-trip tests */
+void test_ai_prefs_round_trip_api_key(void** state);
+void test_ai_prefs_round_trip_remove_key(void** state);
+void test_ai_prefs_multiple_providers_persist(void** state);

tests/unittests/unittests.c

@@ -716,6 +716,65 @@ main(int argc, char* argv[])
         cmocka_unit_test(test_ai_json_escape_special_chars),
         cmocka_unit_test(test_ai_json_escape_percent_signs),
         cmocka_unit_test(test_ai_json_escape_backslash_quote),
+        /* Chat response parser */
+        cmocka_unit_test(test_ai_parse_response_openai_content),
+        cmocka_unit_test(test_ai_parse_response_perplexity_text),
+        cmocka_unit_test(test_ai_parse_response_text_preferred_over_content),
+        cmocka_unit_test(test_ai_parse_response_escaped_quote),
+        cmocka_unit_test(test_ai_parse_response_newline_escape),
+        cmocka_unit_test(test_ai_parse_response_empty_content),
+        cmocka_unit_test(test_ai_parse_response_missing_field),
+        cmocka_unit_test(test_ai_parse_response_null_input),
+        cmocka_unit_test(test_ai_parse_response_empty_input),
+        cmocka_unit_test(test_ai_parse_response_percent_signs_safe),
+        cmocka_unit_test(test_ai_parse_response_braces_in_content),
+        cmocka_unit_test(test_ai_parse_response_multiline_content),
+        /* Error response parser */
+        cmocka_unit_test(test_ai_parse_error_standard_envelope),
+        cmocka_unit_test(test_ai_parse_error_with_escapes),
+        cmocka_unit_test(test_ai_parse_error_no_error_field),
+        cmocka_unit_test(test_ai_parse_error_no_message_field),
+        cmocka_unit_test(test_ai_parse_error_null_input),
+        cmocka_unit_test(test_ai_parse_error_empty_input),
+        cmocka_unit_test(test_ai_parse_error_tab_escape),
+        cmocka_unit_test(test_ai_parse_error_backslash_escape),
+        /* Extended JSON escape coverage */
+        cmocka_unit_test(test_ai_json_escape_backspace),
+        cmocka_unit_test(test_ai_json_escape_formfeed),
+        cmocka_unit_test(test_ai_json_escape_carriage_return),
+        cmocka_unit_test(test_ai_json_escape_all_specials_combined),
+        cmocka_unit_test(test_ai_json_escape_passes_utf8_through),
+        /* Autocomplete cycling */
+        cmocka_unit_test_setup_teardown(test_ai_providers_find_cycles_through_many, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_providers_find_previous_walks_backwards, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_providers_find_wraps_around, ai_client_setup, ai_client_teardown),
+        /* Session edge cases */
+        cmocka_unit_test_setup_teardown(test_ai_session_add_message_null_session_no_crash, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_session_add_message_null_role_no_crash, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_session_add_message_null_content_no_crash, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_session_history_preserves_large_order, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_session_clear_empty_history, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_session_set_model_null_keeps_old, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_session_unref_null_no_crash, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_session_ref_null_returns_null, ai_client_setup, ai_client_teardown),
+        /* Provider edge cases */
+        cmocka_unit_test_setup_teardown(test_ai_get_provider_null_returns_null, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_remove_provider_null_returns_false, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_remove_provider_twice_second_fails, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_provider_survives_via_session_after_removal, ai_client_setup, ai_client_teardown),
+        /* Settings */
+        cmocka_unit_test_setup_teardown(test_ai_settings_multiple_keys_independent, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_settings_get_missing_returns_null, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_settings_isolated_between_providers, ai_client_setup, ai_client_teardown),
+        /* Model parsing edge cases */
+        cmocka_unit_test_setup_teardown(test_ai_parse_models_data_not_array, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_parse_models_empty_data_array, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_parse_models_id_outside_data_ignored, ai_client_setup, ai_client_teardown),
+        cmocka_unit_test_setup_teardown(test_ai_parse_models_multiple_models, ai_client_setup, ai_client_teardown),
+        /* Prefs round-trip (uses prefs+ai setup) */
+        cmocka_unit_test_setup_teardown(test_ai_prefs_round_trip_api_key, ai_client_setup_with_prefs, ai_client_teardown_with_prefs),
+        cmocka_unit_test_setup_teardown(test_ai_prefs_round_trip_remove_key, ai_client_setup_with_prefs, ai_client_teardown_with_prefs),
+        cmocka_unit_test_setup_teardown(test_ai_prefs_multiple_providers_persist, ai_client_setup_with_prefs, ai_client_teardown_with_prefs),
         // Flatfile export/import round-trip
         cmocka_unit_test(test_ff_roundtrip_simple_chat),
         cmocka_unit_test(test_ff_roundtrip_with_all_metadata),