Fix CDS extractor findPackageJsonDirs

This commit:

- fixes a typo in a comment, as identified in a previous PR ( advanced-security#188 );

- updates the logic of the CDS extractor's `findPackageJsonDirs` function;

- fixes a regression in the CDS extractor where a "project directory"
  was not properly recognized when its path was the same as the
  "source root" directory for the CDS extractor scan;

- adds unit tests to cover edge cases idendified for the
  `findPackageJsonDirs` function.

Author: data-douser

extractors/cds/tools/index-files.ts

@@ -42,7 +42,7 @@ if (!envSetupSuccess) {
   process.exit(1);
 }
 
-// Validate response file and get the fully paths of CDS files to process.
+// Validate response file and get the full paths of CDS files to process.
 const filePathsResult = getCdsFilePathsToProcess(responseFile, platformInfo);
 if (!filePathsResult.success) {
   console.warn(filePathsResult.errorMessage);
@@ -54,7 +54,8 @@ if (!filePathsResult.success) {
 const cdsFilePathsToProcess = filePathsResult.cdsFilePaths;
 
 // Find all package.json directories that have a `@sap/cds` node dependency.
-const packageJsonDirs = findPackageJsonDirs(cdsFilePathsToProcess, codeqlExePath);
+// Pass the source root to prevent searching above it
+const packageJsonDirs = findPackageJsonDirs(cdsFilePathsToProcess, codeqlExePath, sourceRoot);
 
 // Install node dependencies in each directory.
 console.log('Pre-installing required CDS compiler versions ...');

extractors/cds/tools/src/packageManager.ts

@@ -14,20 +14,32 @@ export interface PackageJson {
 }
 
 /**
- * Find directories containing package.json with @sap/cds dependency
- * @param filePaths List of CDS file paths to check
- * @param codeqlExePath Path to the CodeQL executable (optional)
- * @returns Set of directories containing relevant package.json files
+ * Find directories containing package.json with a `@sap/cds` dependency.
+ * @param filePaths List of CDS file paths to check.
+ * @param codeqlExePath Path to the CodeQL executable (optional).
+ * @param sourceRoot The source root directory (optional) - Limits the search to
+ * never go above this directory.
+ * @returns Set of directories containing relevant package.json files.
  */
-export function findPackageJsonDirs(filePaths: string[], codeqlExePath?: string): Set<string> {
+export function findPackageJsonDirs(
+  filePaths: string[],
+  codeqlExePath?: string,
+  sourceRoot?: string,
+): Set<string> {
   const packageJsonDirs = new Set<string>();
+  const absoluteSourceRoot = sourceRoot ? resolve(sourceRoot) : undefined;
 
   filePaths.forEach(file => {
     let dir = dirname(resolve(file));
-    const rootDir = dirname(dir); // Keep track of the root to avoid infinite loop
 
-    while (dir !== rootDir && rootDir !== dir) {
-      // Check until we reach the root directory
+    // Check current directory and parent directories for package.json with a
+    // dependency on `@sap/cds`. Never look above the source root directory.
+    while (true) {
+      // Stop if we've reached or gone above the source root directory.
+      if (absoluteSourceRoot && !dir.startsWith(absoluteSourceRoot)) {
+        break;
+      }
+
       const packageJsonPath = join(dir, 'package.json');
       if (existsSync(packageJsonPath)) {
         try {