From d799ff5e6a96b70d3a939a3610a84be350c8cd34 Mon Sep 17 00:00:00 2001
From: Chuan-kai Lin <cklin@github.com>
Date: Thu, 10 Jul 2025 14:14:14 -0700
Subject: [PATCH] Overlay: check per-language features

---
 src/config-utils.test.ts | 68 +++++++++++++++++++++++++++++++++++-----
 src/config-utils.ts      | 30 ++++++++++++++++--
 2 files changed, 89 insertions(+), 9 deletions(-)

diff --git a/src/config-utils.test.ts b/src/config-utils.test.ts
index 9293016dd..04bfe235d 100644
--- a/src/config-utils.test.ts
+++ b/src/config-utils.test.ts
@@ -1345,7 +1345,8 @@ test(
   getOverlayDatabaseModeMacro,
   "Ignore feature flag when analyzing non-default branch",
   {
-    features: [Feature.OverlayAnalysis],
+    languages: [Language.javascript],
+    features: [Feature.OverlayAnalysis, Feature.OverlayAnalysisJavascript],
   },
   {
     overlayDatabaseMode: OverlayDatabaseMode.None,
@@ -1357,7 +1358,8 @@ test(
   getOverlayDatabaseModeMacro,
   "Overlay-base database on default branch when feature enabled",
   {
-    features: [Feature.OverlayAnalysis],
+    languages: [Language.javascript],
+    features: [Feature.OverlayAnalysis, Feature.OverlayAnalysisJavascript],
     isDefaultBranch: true,
   },
   {
@@ -1368,8 +1370,24 @@ test(
 
 test(
   getOverlayDatabaseModeMacro,
-  "No overlay-base database on default branch when feature disabled",
+  "No overlay-base database on default branch when overall feature disabled",
   {
+    languages: [Language.javascript],
+    features: [Feature.OverlayAnalysisJavascript],
+    isDefaultBranch: true,
+  },
+  {
+    overlayDatabaseMode: OverlayDatabaseMode.None,
+    useOverlayDatabaseCaching: false,
+  },
+);
+
+test(
+  getOverlayDatabaseModeMacro,
+  "No overlay-base database on default branch when language-specific feature disabled",
+  {
+    languages: [Language.javascript],
+    features: [Feature.OverlayAnalysis],
     isDefaultBranch: true,
   },
   {
@@ -1382,7 +1400,8 @@ test(
   getOverlayDatabaseModeMacro,
   "Overlay analysis on PR when feature enabled",
   {
-    features: [Feature.OverlayAnalysis],
+    languages: [Language.javascript],
+    features: [Feature.OverlayAnalysis, Feature.OverlayAnalysisJavascript],
     isPullRequest: true,
   },
   {
@@ -1393,8 +1412,24 @@ test(
 
 test(
   getOverlayDatabaseModeMacro,
-  "No overlay analysis on PR when feature disabled",
+  "No overlay analysis on PR when overall feature disabled",
   {
+    languages: [Language.javascript],
+    features: [Feature.OverlayAnalysisJavascript],
+    isPullRequest: true,
+  },
+  {
+    overlayDatabaseMode: OverlayDatabaseMode.None,
+    useOverlayDatabaseCaching: false,
+  },
+);
+
+test(
+  getOverlayDatabaseModeMacro,
+  "No overlay analysis on PR when language-specific feature disabled",
+  {
+    languages: [Language.javascript],
+    features: [Feature.OverlayAnalysis],
     isPullRequest: true,
   },
   {
@@ -1433,7 +1468,8 @@ test(
   getOverlayDatabaseModeMacro,
   "Overlay PR analysis by feature flag for dsp-testing",
   {
-    features: [Feature.OverlayAnalysis],
+    languages: [Language.javascript],
+    features: [Feature.OverlayAnalysis, Feature.OverlayAnalysisJavascript],
     isPullRequest: true,
     repositoryOwner: "dsp-testing",
   },
@@ -1447,7 +1483,8 @@ test(
   getOverlayDatabaseModeMacro,
   "No overlay PR analysis by feature flag for other-org",
   {
-    features: [Feature.OverlayAnalysis],
+    languages: [Language.javascript],
+    features: [Feature.OverlayAnalysis, Feature.OverlayAnalysisJavascript],
     isPullRequest: true,
     repositoryOwner: "other-org",
   },
@@ -1510,3 +1547,20 @@ test(
     useOverlayDatabaseCaching: false,
   },
 );
+
+// Exercise language-specific overlay analysis features code paths
+for (const language in Language) {
+  test(
+    getOverlayDatabaseModeMacro,
+    `Check default overlay analysis feature for ${language}`,
+    {
+      languages: [language as Language],
+      features: [Feature.OverlayAnalysis],
+      isPullRequest: true,
+    },
+    {
+      overlayDatabaseMode: OverlayDatabaseMode.None,
+      useOverlayDatabaseCaching: false,
+    },
+  );
+}
diff --git a/src/config-utils.ts b/src/config-utils.ts
index 94e71a39e..675dd1ea5 100644
--- a/src/config-utils.ts
+++ b/src/config-utils.ts
@@ -646,10 +646,24 @@ function parseQueriesFromInput(
   return trimmedInput.split(",").map((query) => ({ uses: query.trim() }));
 }
 
+const OVERLAY_ANALYSIS_FEATURES: Record<Language, Feature> = {
+  actions: Feature.OverlayAnalysisActions,
+  cpp: Feature.OverlayAnalysisCpp,
+  csharp: Feature.OverlayAnalysisCsharp,
+  go: Feature.OverlayAnalysisGo,
+  java: Feature.OverlayAnalysisJava,
+  javascript: Feature.OverlayAnalysisJavascript,
+  python: Feature.OverlayAnalysisPython,
+  ruby: Feature.OverlayAnalysisRuby,
+  rust: Feature.OverlayAnalysisRust,
+  swift: Feature.OverlayAnalysisSwift,
+};
+
 async function isOverlayAnalysisFeatureEnabled(
   repository: RepositoryNwo,
   features: FeatureEnablement,
   codeql: CodeQL,
+  languages: Language[],
 ): Promise<boolean> {
   // TODO: Remove the repository owner check once support for overlay analysis
   // stabilizes, and no more backward-incompatible changes are expected.
@@ -659,7 +673,14 @@ async function isOverlayAnalysisFeatureEnabled(
   if (!(await features.getValue(Feature.OverlayAnalysis, codeql))) {
     return false;
   }
-  // TODO: Add per-language feature checks here
+  for (const language of languages) {
+    const feature = OVERLAY_ANALYSIS_FEATURES[language];
+    if (feature && (await features.getValue(feature, codeql))) {
+      continue;
+    }
+    // TODO: Add code-scanning feature checks here
+    return false;
+  }
   return true;
 }
 
@@ -713,7 +734,12 @@ export async function getOverlayDatabaseMode(
         "from the CODEQL_OVERLAY_DATABASE_MODE environment variable.",
     );
   } else if (
-    await isOverlayAnalysisFeatureEnabled(repository, features, codeql)
+    await isOverlayAnalysisFeatureEnabled(
+      repository,
+      features,
+      codeql,
+      languages,
+    )
   ) {
     if (isAnalyzingPullRequest()) {
       overlayDatabaseMode = OverlayDatabaseMode.Overlay;