Add prettier lint adapter

pkg/lint/adapter.go

@@ -80,6 +80,7 @@ func defaultAdapters() []Adapter {
 		newCommandAdapter("yamllint", []string{"yamllint"}, []string{"yaml"}, "style", "", false, true, pathArgs("-f", "parsable"), parseTextDiagnostics),
 		newCommandAdapter("jsonlint", []string{"jsonlint"}, []string{"json"}, "style", "", false, true, fileArgs(), parseTextDiagnostics),
 		newCommandAdapter("markdownlint", []string{"markdownlint", "markdownlint-cli"}, []string{"markdown"}, "style", "", false, true, pathArgs("--json"), parseJSONDiagnostics),
+		newCommandAdapter("prettier", []string{"prettier"}, []string{"js"}, "style", "", false, true, pathArgs("--list-different"), parsePrettierDiagnostics),
 		newCommandAdapter("gitleaks", []string{"gitleaks"}, []string{"*"}, "security", "lint.security", true, false, recursivePathArgs("detect", "--no-git", "--report-format", "json", "--source"), parseJSONDiagnostics),
 		newCommandAdapter("trivy", []string{"trivy"}, []string{"*"}, "security", "lint.security", true, false, pathArgs("fs", "--format", "json"), parseJSONDiagnostics),
 		newCommandAdapter("semgrep", []string{"semgrep"}, []string{"*"}, "security", "lint.security", true, false, pathArgs("--json"), parseJSONDiagnostics),
@@ -598,6 +599,28 @@ func parseTextDiagnostics(tool string, category string, output string) []Finding
 	return dedupeFindings(findings)
 }
 
+func parsePrettierDiagnostics(tool string, category string, output string) []Finding {
+	var findings []Finding
+
+	for line := range strings.SplitSeq(strings.TrimSpace(output), "\n") {
+		trimmed := strings.TrimSpace(line)
+		if trimmed == "" {
+			continue
+		}
+
+		findings = append(findings, Finding{
+			Tool:     tool,
+			File:     filepath.ToSlash(trimmed),
+			Severity: defaultSeverityForCategory(category),
+			Code:     "prettier-format",
+			Message:  "File is not formatted with Prettier",
+			Category: category,
+		})
+	}
+
+	return dedupeFindings(findings)
+}
+
 func parseTextDiagnosticLine(tool string, category string, line string) (Finding, bool) {
 	segments := strings.Split(line, ":")
 	if len(segments) < 3 {

pkg/lint/service_test.go

@@ -90,6 +90,34 @@ func run2() {
 	assert.False(t, report.Summary.Passed)
 }
 
+func TestServiceRun_JS_PrettierFindings(t *testing.T) {
+	dir := t.TempDir()
+	require.NoError(t, os.WriteFile(filepath.Join(dir, "package.json"), []byte("{\n  \"name\": \"example\"\n}\n"), 0o644))
+	require.NoError(t, os.WriteFile(filepath.Join(dir, "index.js"), []byte("const value = 1;\n"), 0o644))
+
+	setupMockCmdExit(t, "prettier", "index.js\n", "", 1)
+
+	svc := &Service{adapters: []Adapter{
+		newCommandAdapter("prettier", []string{"prettier"}, []string{"js"}, "style", "", false, true, pathArgs("--list-different"), parsePrettierDiagnostics),
+	}}
+	report, err := svc.Run(context.Background(), RunInput{
+		Path:   dir,
+		FailOn: "warning",
+	})
+	require.NoError(t, err)
+
+	require.Len(t, report.Findings, 1)
+	require.Len(t, report.Tools, 1)
+	assert.Equal(t, "prettier", report.Findings[0].Tool)
+	assert.Equal(t, "index.js", report.Findings[0].File)
+	assert.Equal(t, "prettier-format", report.Findings[0].Code)
+	assert.Equal(t, "warning", report.Findings[0].Severity)
+	assert.False(t, report.Summary.Passed)
+	assert.Equal(t, "prettier", report.Tools[0].Name)
+	assert.Equal(t, "failed", report.Tools[0].Status)
+	assert.Equal(t, 1, report.Tools[0].Findings)
+}
+
 func runTestCommand(t *testing.T, dir string, name string, args ...string) {
 	t.Helper()