fix: create the first persistent artifact on the incremental path

src/pipeline/pipeline.c

@@ -296,6 +296,10 @@ const char *cbm_pipeline_project_name(const cbm_pipeline_t *p) {
     return p ? p->project_name : NULL;
 }
 
+bool cbm_pipeline_persistence(const cbm_pipeline_t *p) {
+    return p && p->persistence;
+}
+
 const char *cbm_pipeline_repo_path(const cbm_pipeline_t *p) {
     return p ? p->repo_path : NULL;
 }

src/pipeline/pipeline.h

@@ -72,6 +72,9 @@ void cbm_pipeline_bind_cancel_flag(cbm_pipeline_t *p, atomic_int *cancelled);
  * owned by the pipeline. Valid until cbm_pipeline_free(). */
 const char *cbm_pipeline_project_name(const cbm_pipeline_t *p);
 
+/* Return whether persistent artifact export is enabled for this pipeline. */
+bool cbm_pipeline_persistence(const cbm_pipeline_t *p);
+
 /* Override the derived project name with a sanitized user-provided label. */
 bool cbm_pipeline_set_project_name(cbm_pipeline_t *p, const char *name);
 

src/pipeline/pipeline_incremental.c

@@ -13,6 +13,7 @@
 
 enum { INCR_RING_BUF = 4, INCR_RING_MASK = 3, INCR_TS_BUF = 24 };
 #include "pipeline/pipeline.h"
+#include "pipeline/artifact.h"
 #include <stdio.h>
 #include <time.h>
 #include "pipeline/pipeline_internal.h"
@@ -640,8 +641,8 @@ static void run_postpasses(cbm_pipeline_ctx_t *ctx, cbm_file_info_t *changed_fil
 static int dump_and_persist(cbm_gbuf_t *gbuf, const char *db_path, const char *project,
                             cbm_file_info_t *files, int file_count,
                             const cbm_file_hash_t *mode_skipped, int mode_skipped_count,
-                            const cbm_coverage_row_t *cov, int cov_count,
-                            const cbm_coverage_meta_t *meta_template) {
+                            const char *repo_path, bool persistence, const cbm_coverage_row_t *cov,
+                            int cov_count, const cbm_coverage_meta_t *meta_template) {
     struct timespec t;
     cbm_clock_gettime(CLOCK_MONOTONIC, &t);
 
@@ -701,6 +702,20 @@ static int dump_and_persist(cbm_gbuf_t *gbuf, const char *db_path, const char *p
         }
     }
     cbm_store_close(hash_store);
+
+    /* Create a requested artifact, or cheaply refresh one that already exists.
+     * Runs after the store is closed so the export reads a settled DB file. */
+    bool artifact_exists = repo_path && cbm_artifact_exists(repo_path);
+    if (repo_path && (persistence || artifact_exists)) {
+        int arc = cbm_artifact_export(db_path, repo_path, project,
+                                      artifact_exists ? CBM_ARTIFACT_FAST : CBM_ARTIFACT_BEST);
+        if (arc != 0) {
+            const char *err = cbm_artifact_export_last_error();
+            cbm_log_error("pipeline.err", "phase", "artifact_export", "err", err ? err : "unknown");
+            return arc;
+        }
+    }
+
     return rc;
 }
 
@@ -749,12 +764,22 @@ int cbm_pipeline_run_incremental(cbm_pipeline_t *p, const char *db_path, cbm_fil
      * that were already preserved by an earlier run) remain intact. */
     if (n_changed == 0 && deleted_count == 0) {
         cbm_log_info("incremental.noop", "reason", "no_changes");
+        int arc = 0;
+        const char *repo_path = cbm_pipeline_repo_path(p);
+        if (cbm_pipeline_persistence(p) && repo_path && !cbm_artifact_exists(repo_path)) {
+            arc = cbm_artifact_export(db_path, repo_path, project, CBM_ARTIFACT_BEST);
+            if (arc != 0) {
+                const char *err = cbm_artifact_export_last_error();
+                cbm_log_error("pipeline.err", "phase", "artifact_export", "err",
+                              err ? err : "unknown");
+            }
+        }
         free(is_changed);
         free(deleted);
         free_mode_skipped(mode_skipped, mode_skipped_count);
         cbm_store_free_file_hashes(stored, stored_count);
         cbm_store_close(store);
-        return 0;
+        return arc;
     }
 
     cbm_store_free_file_hashes(stored, stored_count);
@@ -1007,7 +1032,8 @@ int cbm_pipeline_run_incremental(cbm_pipeline_t *p, const char *db_path, cbm_fil
         .coverage_version = 1,
     };
     int persist_rc = dump_and_persist(existing, db_path, project, files, file_count, mode_skipped,
-                                      mode_skipped_count, cov, cov_n, &coverage_meta);
+                                      mode_skipped_count, cbm_pipeline_repo_path(p),
+                                      cbm_pipeline_persistence(p), cov, cov_n, &coverage_meta);
     free(cov);
     cbm_store_free_coverage(old_cov, old_cov_count);
     free_mode_skipped(mode_skipped, mode_skipped_count);

tests/test_pipeline.c

@@ -11,6 +11,7 @@
 #include "foundation/mem.h" // cbm_mem_init/budget (back-pressure futile-nap test)
 #include "pipeline/pipeline.h"
 #include "pipeline/pipeline_internal.h"
+#include "pipeline/artifact.h"
 #include "store/store.h"
 #include "git/git_context.h"
 #include "foundation/dump_verify.h"
@@ -5761,6 +5762,62 @@ TEST(incremental_full_then_noop) {
     PASS();
 }
 
+TEST(incremental_persistence_creates_first_artifact) {
+    /* Populate the local DB without persistence, then change a file and
+     * enable persistence on the incremental path. The first artifact must be
+     * created here rather than waiting for a later reindex. */
+    if (setup_incremental_repo() != 0) {
+        FAIL("setup failed");
+    }
+
+    cbm_pipeline_t *p = cbm_pipeline_new(g_incr_tmpdir, g_incr_dbpath, CBM_MODE_FULL);
+    ASSERT_NOT_NULL(p);
+    ASSERT_EQ(cbm_pipeline_run(p), 0);
+    cbm_pipeline_free(p);
+
+    ASSERT_FALSE(cbm_artifact_exists(g_incr_tmpdir));
+
+    char path[512];
+    snprintf(path, sizeof(path), "%s/helper.go", g_incr_tmpdir);
+    ASSERT_EQ(th_append_file(path, "\n// persistence regression marker\n"), 0);
+
+    p = cbm_pipeline_new(g_incr_tmpdir, g_incr_dbpath, CBM_MODE_FULL);
+    ASSERT_NOT_NULL(p);
+    cbm_pipeline_set_persistence(p, true);
+    ASSERT_EQ(cbm_pipeline_run(p), 0);
+    ASSERT_TRUE(cbm_artifact_exists(g_incr_tmpdir));
+    cbm_pipeline_free(p);
+
+    cleanup_incremental_repo();
+    PASS();
+}
+
+TEST(incremental_noop_persistence_creates_first_artifact) {
+    /* Populate the local DB without persistence, then request persistence
+     * without changing any files. The incremental no-op path must still
+     * create the missing artifact. */
+    if (setup_incremental_repo() != 0) {
+        FAIL("setup failed");
+    }
+
+    cbm_pipeline_t *p = cbm_pipeline_new(g_incr_tmpdir, g_incr_dbpath, CBM_MODE_FULL);
+    ASSERT_NOT_NULL(p);
+    ASSERT_EQ(cbm_pipeline_run(p), 0);
+    cbm_pipeline_free(p);
+
+    ASSERT_FALSE(cbm_artifact_exists(g_incr_tmpdir));
+
+    p = cbm_pipeline_new(g_incr_tmpdir, g_incr_dbpath, CBM_MODE_FULL);
+    ASSERT_NOT_NULL(p);
+    cbm_pipeline_set_persistence(p, true);
+    ASSERT_EQ(cbm_pipeline_run(p), 0);
+    ASSERT_TRUE(cbm_artifact_exists(g_incr_tmpdir));
+    cbm_pipeline_free(p);
+
+    cleanup_incremental_repo();
+    PASS();
+}
+
 TEST(incremental_detects_changed_file) {
     /* Full index, modify one file, re-index → changed file re-parsed */
     if (setup_incremental_repo() != 0) {
@@ -7506,6 +7563,8 @@ SUITE(pipeline) {
     RUN_TEST(pipeline_fastapi_depends_edges);
     /* Incremental */
     RUN_TEST(incremental_full_then_noop);
+    RUN_TEST(incremental_persistence_creates_first_artifact);
+    RUN_TEST(incremental_noop_persistence_creates_first_artifact);
     RUN_TEST(incremental_detects_changed_file);
     RUN_TEST(incremental_aborts_when_previous_coverage_is_unreadable);
     RUN_TEST(incremental_detects_deleted_file);