refactor(testrunner): improve lint execution and error handling for multiple work directories

Refactor lint execution to support multiple work directories via StartingPaths, enabling proper linter config discovery relative to each directory rather than the git root.

Changes:
- Add lintWorkDirs() helper to resolve StartingPaths into absolute WorkDir values
- Update lint execution to iterate over resolved directories and aggregate results
- Add lint dry-run support during test execution when Lint option is enabled
- Change detectAndRun() to log info messages instead of returning errors when no frameworks or test packages are found, allowing graceful handling of empty test scenarios
- Add null check for diagnostics in UI snapshot application to prevent overwriting with undefined
- Simplify diagnostics availability check in useEffect hook

This enables more flexible test and lint execution patterns while improving error messaging and UI stability.

Author: moshloop

cmd/gavel/test.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"os/exec"
 	"os/signal"
+	"path/filepath"
 	"runtime"
 	"strconv"
 	"strings"
@@ -80,6 +81,13 @@ func runTests(opts testrunner.RunOptions) (any, error) {
 		if _, err := testrunner.Run(opts); err != nil {
 			return nil, err
 		}
+		if opts.Lint {
+			for _, workDir := range lintWorkDirs(opts.WorkDir, opts.StartingPaths) {
+				if err := displayLintDryRun(LintOptions{WorkDir: workDir, Timeout: "5m"}); err != nil {
+					return nil, err
+				}
+			}
+		}
 		if !opts.SkipHooks {
 			printDryRunHooks(opts.WorkDir, gavelCfg.Post, "post-hook")
 		}
@@ -160,10 +168,14 @@ func runTests(opts testrunner.RunOptions) (any, error) {
 			if workDir == "" {
 				workDir, _ = os.Getwd()
 			}
-			lintResults, lintErr = executeLinters(LintOptions{
-				WorkDir: workDir,
-				Timeout: "5m",
-			})
+			for _, dir := range lintWorkDirs(workDir, opts.StartingPaths) {
+				results, err := executeLinters(LintOptions{WorkDir: dir, Timeout: "5m"})
+				if err != nil {
+					lintErr = err
+					break
+				}
+				lintResults = append(lintResults, results...)
+			}
 			if lintErr == nil {
 				linters.FilterIgnoredViolations(lintResults, gavelCfg.Lint.Ignore)
 			}
@@ -262,6 +274,31 @@ func printDryRunHooks(workDir string, hooks []verify.HookStep, label string) {
 	}
 }
 
+// lintWorkDirs resolves StartingPaths into WorkDir values for the lint
+// codepath. Each directory path becomes its own WorkDir so linter config
+// discovery happens relative to that directory (not the git root).
+// When no paths are given, the fallback WorkDir is returned.
+func lintWorkDirs(fallback string, startingPaths []string) []string {
+	if len(startingPaths) == 0 {
+		return []string{fallback}
+	}
+	var dirs []string
+	for _, p := range startingPaths {
+		abs := p
+		if !filepath.IsAbs(p) {
+			abs = filepath.Join(fallback, p)
+		}
+		abs, _ = filepath.Abs(abs)
+		if info, err := os.Stat(abs); err == nil && info.IsDir() {
+			dirs = append(dirs, abs)
+		}
+	}
+	if len(dirs) == 0 {
+		return []string{fallback}
+	}
+	return dirs
+}
+
 // runPushHooksReportingUI runs verify's hook list while also publishing
 // each step to the testui (when active) as a pseudo-test: pending while
 // running, passed or failed on completion. When the UI is not active,

testrunner/runner.go

@@ -619,7 +619,8 @@ func escapeRegexNames(names []string) []string {
 
 func (o *TestOrchestrator) detectAndRun(frameworks []Framework, startingPaths []string, extraArgs []string) (parsers.TestSuiteResults, error) {
 	if len(frameworks) == 0 {
-		return nil, fmt.Errorf("no frameworks provided for test execution")
+		logger.Infof("No test frameworks detected")
+		return nil, nil
 	}
 	// Validate that starting paths exist
 	if len(startingPaths) > 0 {
@@ -676,9 +677,11 @@ func (o *TestOrchestrator) detectAndRun(frameworks []Framework, startingPaths []
 
 	if len(allPackages) == 0 {
 		if len(startingPaths) > 0 {
-			return nil, fmt.Errorf("no test packages found in starting paths %v", startingPaths)
+			logger.Infof("No test packages found in starting paths %v", startingPaths)
+		} else {
+			logger.Infof("No test packages found")
 		}
-		return nil, fmt.Errorf("no test packages found")
+		return nil, nil
 	}
 
 	// Narrow via change graph and/or run cache. Both selectors share a

testrunner/ui/src/App.tsx

@@ -61,7 +61,7 @@ function applySnapshot(
   setLintRun(!!status.lint_run);
   setBench(snap.bench);
   setDiagnosticsAvailable(!!status.diagnostics_available);
-  setDiagnostics(snap.diagnostics);
+  if (snap.diagnostics) setDiagnostics(snap.diagnostics);
   setRunMeta(meta);
   if (!status.running) {
     doneRef.current = true;
@@ -222,10 +222,7 @@ export function App() {
   }, []);
 
   useEffect(() => {
-    if (!diagnosticsAvailable) {
-      setDiagnostics(undefined);
-      return;
-    }
+    if (!diagnosticsAvailable) return;
 
     fetchDiagnostics().catch(() => {});
     const timer = window.setInterval(() => {