Use a plain Set intead of custom FilePathSet

extensions/ql-vscode/src/common/file-path-set.ts

@@ -1,42 +0,0 @@
-import { containsPath } from "../pure/files";
-
-/**
- * A set of file paths.
- *
- * All paths in the set will not overlap. If a path is added to the set
- * that is a parent or child of an existing path in the set, only the
- * parent path will be kept.
- */
-export class FilePathSet {
-  private paths: string[] = [];
-
-  /** Is the set currently empty */
-  public isEmpty(): boolean {
-    return this.paths.length === 0;
-  }
-
-  /**
-   * Adds the path to the set.
-   *
-   * The set will not contain overlapping paths. This means that if the
-   * new path is a child of an existing path in the set then it will not
-   * be added. And if the new path is a parent of any existing paths, then
-   * those existing paths will be removed. This can cause the "size" of
-   * the set of decrease, but it won't go from non-zero to zero.
-   */
-  public addPath(path: string): void {
-    if (this.paths.some((p) => containsPath(p, path))) {
-      // The new path is a child of an existing path, so don't add it.
-      return;
-    } else {
-      // Remove any existing paths that are children of the new path.
-      this.paths = this.paths.filter((p) => !containsPath(path, p));
-      this.paths.push(path);
-    }
-  }
-
-  /** Removes and returns a path from the set, if the set is non-empty. */
-  public popPath(): string | undefined {
-    return this.paths.shift();
-  }
-}

extensions/ql-vscode/src/common/vscode/file-path-discovery.ts

@@ -9,7 +9,6 @@ import {
 import { MultiFileSystemWatcher } from "./multi-file-system-watcher";
 import { AppEventEmitter } from "../events";
 import { extLogger } from "..";
-import { FilePathSet } from "../file-path-set";
 import { exists, lstat } from "fs-extra";
 import { containsPath } from "../../pure/files";
 import { getOnDiskWorkspaceFoldersObjects } from "./workspace-folders";
@@ -30,9 +29,23 @@ interface PathData {
 export abstract class FilePathDiscovery<T extends PathData> extends Discovery {
   /** The set of known paths we are tracking */
   protected paths: T[] = [];
+
+  /** Event that fires whenever the set of known paths changes */
   protected readonly onDidChangePathsEmitter: AppEventEmitter<void>;
 
-  private readonly changedFilePaths = new FilePathSet();
+  /**
+   * The set of file paths that may have changed on disk since the last time
+   * refresh was run. Whenever a watcher reports some change to a file we add
+   * it to this set, and then during the next refresh we will process all
+   * file paths from this set and update our internal state to match whatever
+   * we find on disk (i.e. the file exists, doesn't exist, computed data has
+   * changed).
+   */
+  private readonly changedFilePaths = new Set<string>();
+
+  /**
+   * Watches for changes to files and directories in all workspace folders.
+   */
   private readonly watcher: MultiFileSystemWatcher = this.push(
     new MultiFileSystemWatcher(),
   );
@@ -76,7 +89,7 @@ export abstract class FilePathDiscovery<T extends PathData> extends Discovery {
    */
   public async initialRefresh() {
     getOnDiskWorkspaceFoldersObjects().forEach((workspaceFolder) => {
-      this.changedFilePaths.addPath(workspaceFolder.uri.fsPath);
+      this.changedFilePaths.add(workspaceFolder.uri.fsPath);
     });
 
     this.updateWatchers();
@@ -85,10 +98,10 @@ export abstract class FilePathDiscovery<T extends PathData> extends Discovery {
 
   private workspaceFoldersChanged(event: WorkspaceFoldersChangeEvent) {
     event.added.forEach((workspaceFolder) => {
-      this.changedFilePaths.addPath(workspaceFolder.uri.fsPath);
+      this.changedFilePaths.add(workspaceFolder.uri.fsPath);
     });
     event.removed.forEach((workspaceFolder) => {
-      this.changedFilePaths.addPath(workspaceFolder.uri.fsPath);
+      this.changedFilePaths.add(workspaceFolder.uri.fsPath);
     });
 
     this.updateWatchers();
@@ -108,14 +121,14 @@ export abstract class FilePathDiscovery<T extends PathData> extends Discovery {
   }
 
   private fileChanged(uri: Uri) {
-    this.changedFilePaths.addPath(uri.fsPath);
+    this.changedFilePaths.add(uri.fsPath);
     void this.refresh();
   }
 
   protected async discover() {
     let pathsUpdated = false;
-    let path: string | undefined;
+    for (const path of this.changedFilePaths) {
-    while ((path = this.changedFilePaths.popPath()) !== undefined) {
+      this.changedFilePaths.delete(path);
       if (await this.handledChangedPath(path)) {
         pathsUpdated = true;
       }

extensions/ql-vscode/test/unit-tests/common/file-path-set.test.ts

@@ -1,58 +0,0 @@
-import { FilePathSet } from "../../../src/common/file-path-set";
-
-describe("FilePathSet", () => {
-  describe("isEmpty", () => {
-    it("should return true only when set is empty", () => {
-      const v = new FilePathSet();
-      expect(v.isEmpty()).toBe(true);
-
-      v.addPath("/foo");
-      expect(v.isEmpty()).toBe(false);
-
-      v.popPath();
-      expect(v.isEmpty()).toBe(true);
-    });
-  });
-
-  describe("addPath / popPath", () => {
-    it("should keep all paths when they don't overlap", () => {
-      const v = new FilePathSet();
-      v.addPath("/foo");
-      v.addPath("/bar");
-      v.addPath("/baz");
-      expect(v.popPath()).toBe("/foo");
-      expect(v.popPath()).toBe("/bar");
-      expect(v.popPath()).toBe("/baz");
-      expect(v.popPath()).toBe(undefined);
-    });
-
-    it("should only keep one copy of repeated paths", () => {
-      const v = new FilePathSet();
-      v.addPath("/foo");
-      v.addPath("/foo");
-      v.addPath("/foo");
-      expect(v.popPath()).toBe("/foo");
-      expect(v.popPath()).toBe(undefined);
-    });
-
-    it("should adding adding paths that are children of existing paths", () => {
-      const v = new FilePathSet();
-      v.addPath("/foo");
-      v.addPath("/foo/bar");
-      v.addPath("/foo/baz");
-      expect(v.popPath()).toBe("/foo");
-      expect(v.popPath()).toBe(undefined);
-    });
-
-    it("should remove existing paths that are children of new paths", () => {
-      const v = new FilePathSet();
-      v.addPath("/foo");
-      v.addPath("/bar/baz");
-      v.addPath("/bar/qux");
-      v.addPath("/bar");
-      expect(v.popPath()).toBe("/foo");
-      expect(v.popPath()).toBe("/bar");
-      expect(v.popPath()).toBe(undefined);
-    });
-  });
-});