Treat Daily Go Function Namer cache cold starts as expected state (#31331)

Author: Copilot

.github/workflows/daily-function-namer.md

@@ -131,6 +131,8 @@ The script outputs:
 
 Use these values directly for the rest of the workflow. Do **not** re-derive or re-compute them manually.
 
+**On cold start** (`/tmp/gh-aw/cache-memory/function-namer-state.json` missing): treat this as expected initialization, not a failure. Do **not** call `missing_data` for a missing state file on first run or cold cache; run the Step 1 script as written, accept `LAST_INDEX=-1`, and continue.
+
 ## Step 2: Enumerate All Functions in the Package
 
 Before invoking Serena, run a fast `grep` sweep across all files in the selected package to build a complete function inventory. This minimizes Serena tool calls by giving you the full picture upfront:
@@ -242,6 +244,8 @@ Use relative paths (e.g., `pkg/workflow`) matching the output of the `find pkg`
 
 Prune `analyzed_packages` to the most recent 30 entries to prevent unbounded growth.
 
+If the state file was missing at the start of the run, initialize it from scratch here instead of reporting missing cache data.
+
 ## Step 6: Create Issue with Agentic Plan
 
 If any rename suggestions were found across the analyzed package, create a GitHub issue.

pkg/workflow/prompts_test.go

@@ -217,6 +217,30 @@ This is a test workflow with multiple cache-memory entries.
 	t.Logf("Successfully verified cache memory instructions handle multiple caches")
 }
 
+func TestDailyFunctionNamerColdStartHandling(t *testing.T) {
+	repoRoot, err := findRepoRoot()
+	if err != nil {
+		t.Fatalf("Failed to find repo root: %v", err)
+	}
+
+	workflowFile := filepath.Join(repoRoot, ".github", "workflows", "daily-function-namer.md")
+	content, err := os.ReadFile(workflowFile)
+	if err != nil {
+		t.Fatalf("Failed to read workflow file: %v", err)
+	}
+
+	workflow := string(content)
+	coldStartGuidance := "**On cold start** (`/tmp/gh-aw/cache-memory/function-namer-state.json` missing): treat this as expected initialization, not a failure. Do **not** call `missing_data` for a missing state file on first run or cold cache; run the Step 1 script as written, accept `LAST_INDEX=-1`, and continue."
+	if !strings.Contains(workflow, coldStartGuidance) {
+		t.Fatal("Expected daily-function-namer workflow to include explicit cold-start guidance")
+	}
+
+	stepFiveGuidance := "If the state file was missing at the start of the run, initialize it from scratch here instead of reporting missing cache data."
+	if !strings.Contains(workflow, stepFiveGuidance) {
+		t.Fatal("Expected daily-function-namer workflow to initialize missing cold-start state instead of reporting missing data")
+	}
+}
+
 // ============================================================================
 // Playwright Prompt Tests
 // ============================================================================