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)

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