From 1994ea768eb3060a022857b2e7d2fea058610022 Mon Sep 17 00:00:00 2001
From: Chuan-kai Lin <cklin@github.com>
Date: Thu, 27 Mar 2025 10:17:31 -0700
Subject: [PATCH] Move shouldPerformDiffInformedAnalysis()

---
 src/analyze.ts                      | 61 +---------------------------
 src/diff-informed-analysis-utils.ts | 62 +++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 59 deletions(-)

diff --git a/src/analyze.ts b/src/analyze.ts
index db5c737aa..b11219aa2 100644
--- a/src/analyze.ts
+++ b/src/analyze.ts
@@ -2,7 +2,6 @@ import * as fs from "fs";
 import * as path from "path";
 import { performance } from "perf_hooks";
 
-import * as github from "@actions/github";
 import * as io from "@actions/io";
 import del from "del";
 import * as yaml from "js-yaml";
@@ -16,6 +15,8 @@ import { getJavaTempDependencyDir } from "./dependency-caching";
 import { addDiagnostic, makeDiagnostic } from "./diagnostics";
 import {
   DiffThunkRange,
+  PullRequestBranches,
+  shouldPerformDiffInformedAnalysis,
   writeDiffRangesJsonFile,
 } from "./diff-informed-analysis-utils";
 import { EnvVar } from "./environment";
@@ -255,64 +256,6 @@ async function finalizeDatabaseCreation(
   };
 }
 
-interface PullRequestBranches {
-  base: string;
-  head: string;
-}
-
-function getPullRequestBranches(): PullRequestBranches | undefined {
-  const pullRequest = github.context.payload.pull_request;
-  if (pullRequest) {
-    return {
-      base: pullRequest.base.ref,
-      // We use the head label instead of the head ref here, because the head
-      // ref lacks owner information and by itself does not uniquely identify
-      // the head branch (which may be in a forked repository).
-      head: pullRequest.head.label,
-    };
-  }
-
-  // PR analysis under Default Setup does not have the pull_request context,
-  // but it should set CODE_SCANNING_REF and CODE_SCANNING_BASE_BRANCH.
-  const codeScanningRef = process.env.CODE_SCANNING_REF;
-  const codeScanningBaseBranch = process.env.CODE_SCANNING_BASE_BRANCH;
-  if (codeScanningRef && codeScanningBaseBranch) {
-    return {
-      base: codeScanningBaseBranch,
-      // PR analysis under Default Setup analyzes the PR head commit instead of
-      // the merge commit, so we can use the provided ref directly.
-      head: codeScanningRef,
-    };
-  }
-  return undefined;
-}
-
-/**
- * Check if the action should perform diff-informed analysis.
- *
- * @returns If the action should perform diff-informed analysis, return
- * the base and head branches that should be used to compute the diff ranges.
- * Otherwise return `undefined`.
- */
-async function shouldPerformDiffInformedAnalysis(
-  codeql: CodeQL,
-  features: FeatureEnablement,
-  logger: Logger,
-): Promise<PullRequestBranches | undefined> {
-  if (!(await features.getValue(Feature.DiffInformedQueries, codeql))) {
-    return undefined;
-  }
-
-  const branches = getPullRequestBranches();
-  if (!branches) {
-    logger.info(
-      "Not performing diff-informed analysis " +
-        "because we are not analyzing a pull request.",
-    );
-  }
-  return branches;
-}
-
 /**
  * Set up the diff-informed analysis feature.
  *
diff --git a/src/diff-informed-analysis-utils.ts b/src/diff-informed-analysis-utils.ts
index 22754fb24..611be3622 100644
--- a/src/diff-informed-analysis-utils.ts
+++ b/src/diff-informed-analysis-utils.ts
@@ -1,9 +1,71 @@
 import * as fs from "fs";
 import * as path from "path";
 
+import * as github from "@actions/github";
+
 import * as actionsUtil from "./actions-util";
+import type { CodeQL } from "./codeql";
+import { Feature, FeatureEnablement } from "./feature-flags";
 import { Logger } from "./logging";
 
+export interface PullRequestBranches {
+  base: string;
+  head: string;
+}
+
+function getPullRequestBranches(): PullRequestBranches | undefined {
+  const pullRequest = github.context.payload.pull_request;
+  if (pullRequest) {
+    return {
+      base: pullRequest.base.ref,
+      // We use the head label instead of the head ref here, because the head
+      // ref lacks owner information and by itself does not uniquely identify
+      // the head branch (which may be in a forked repository).
+      head: pullRequest.head.label,
+    };
+  }
+
+  // PR analysis under Default Setup does not have the pull_request context,
+  // but it should set CODE_SCANNING_REF and CODE_SCANNING_BASE_BRANCH.
+  const codeScanningRef = process.env.CODE_SCANNING_REF;
+  const codeScanningBaseBranch = process.env.CODE_SCANNING_BASE_BRANCH;
+  if (codeScanningRef && codeScanningBaseBranch) {
+    return {
+      base: codeScanningBaseBranch,
+      // PR analysis under Default Setup analyzes the PR head commit instead of
+      // the merge commit, so we can use the provided ref directly.
+      head: codeScanningRef,
+    };
+  }
+  return undefined;
+}
+
+/**
+ * Check if the action should perform diff-informed analysis.
+ *
+ * @returns If the action should perform diff-informed analysis, return
+ * the base and head branches that should be used to compute the diff ranges.
+ * Otherwise return `undefined`.
+ */
+export async function shouldPerformDiffInformedAnalysis(
+  codeql: CodeQL,
+  features: FeatureEnablement,
+  logger: Logger,
+): Promise<PullRequestBranches | undefined> {
+  if (!(await features.getValue(Feature.DiffInformedQueries, codeql))) {
+    return undefined;
+  }
+
+  const branches = getPullRequestBranches();
+  if (!branches) {
+    logger.info(
+      "Not performing diff-informed analysis " +
+        "because we are not analyzing a pull request.",
+    );
+  }
+  return branches;
+}
+
 export interface DiffThunkRange {
   path: string;
   startLine: number;