Merge pull request #637 from snyk/fix_common_dir_bug

fix: common extracted dir bug

lib/analyzer/applications/runtime-common.ts

@@ -10,34 +10,43 @@ export function getAppFilesRootDir(
   filePaths: string[],
 ): [string, ApplicationFileInfo[]] {
   const appFiles: ApplicationFileInfo[] = [];
-  let rootDir: string = "";
-  const directories: Set<string> = new Set();
+  const splitPaths: string[][] = [];
+
+  if (!filePaths.length) {
+    return [path.sep, appFiles];
+  }
 
   for (const filePath of filePaths) {
     appFiles.push({ path: filePath });
-    directories.add(path.dirname(filePath)); // Collect directories of app files
+    splitPaths.push(filePath.split("/").filter(Boolean));
   }
 
-  // Determine the common directory
-  if (appFiles.length > 0) {
-    rootDir = Array.from(directories).reduce((commonDir, dir) => {
-      // Find the common path
-      while (commonDir && commonDir !== "" && !dir.startsWith(commonDir)) {
-        commonDir = commonDir.substring(0, commonDir.lastIndexOf(path.sep));
-      }
-      return commonDir;
-    }, directories.values().next().value);
+  // Find the shortest path length to prevent out-of-bounds access
+  const minLength = Math.min(...splitPaths.map((path) => path.length));
+
+  // Find the common parts of the paths
+  const commonParts: string[] = [];
+  for (let i = 0; i < minLength - 1; i++) {
+    const currentPart = splitPaths[0][i];
+    if (splitPaths.every((path) => path[i] === currentPart)) {
+      commonParts.push(currentPart);
+    } else {
+      break;
+    }
   }
 
+  // Join the common parts to form the common directory
+  const rootDir = "/" + commonParts.join("/");
+
   // Remove the common path prefix from each appFile
   appFiles.forEach((file) => {
-    const prefix = `${rootDir}${path.sep}`;
+    const prefix = rootDir === path.sep ? rootDir : `${rootDir}${path.sep}`;
     if (file.path.startsWith(prefix)) {
       file.path = file.path.substring(prefix.length); // Remove rootDir from path
     }
   });
 
-  return [rootDir, appFiles];
+  return [rootDir || path.sep, appFiles];
 }
 
 export function getApplicationFiles(

test/system/application-scans/node.spec.ts

@@ -663,7 +663,18 @@ describe("node application files grouping", () => {
   });
 
   it("should correctly group js ts files with root dir", async () => {
-    const nodeProjectFiles = [
+    let nodeProjectFiles = [
+      "/aaa/bbb/ccc/y.js",
+      "/aaa/bbb/ccc/z.js",
+      "/aaa/x.js",
+    ];
+
+    let [appFilesRootDir, appFiles] = getAppFilesRootDir(nodeProjectFiles);
+
+    expect(appFilesRootDir).toBe("/aaa");
+    expect(appFiles.length).toBe(3);
+
+    nodeProjectFiles = [
       "/srv/dist/index.js",
       "/srv/dist/src/app.js",
       "/srv/dist/src/utils/helpers.js",
@@ -676,7 +687,7 @@ describe("node application files grouping", () => {
       "/srv/dist/package-lock.json",
     ];
 
-    const [appFilesRootDir, appFiles] = getAppFilesRootDir(nodeProjectFiles);
+    [appFilesRootDir, appFiles] = getAppFilesRootDir(nodeProjectFiles);
 
     expect(appFilesRootDir).toBe("/srv/dist");
     expect(appFiles.length).toBe(10);
@@ -693,6 +704,30 @@ describe("node application files grouping", () => {
       { path: "package-lock.json" },
     ]);
   });
+
+  it("should return / as the root dir in case nothing's found", async () => {
+    const nodeProjectFiles = ["/srv/dist/index.js", "/opt/app.js"];
+
+    const [appFilesRootDir, appFiles] = getAppFilesRootDir(nodeProjectFiles);
+    expect(appFilesRootDir).toBe("/");
+    expect(appFiles.length).toBe(2);
+    expect(appFiles).toEqual([
+      { path: "srv/dist/index.js" },
+      { path: "opt/app.js" },
+    ]);
+  });
+
+  it("should only consider full path segments for common prefix", async () => {
+    const nodeProjectFiles = ["/srv/dist/index.js", "/srv2/app.js"];
+
+    const [appFilesRootDir, appFiles] = getAppFilesRootDir(nodeProjectFiles);
+    expect(appFilesRootDir).toBe("/");
+    expect(appFiles.length).toBe(2);
+    expect(appFiles).toEqual([
+      { path: "srv/dist/index.js" },
+      { path: "srv2/app.js" },
+    ]);
+  });
 });
 
 describe("Edge testing of node modules scan utils functions", () => {