Ensure src.zip is prioritized over src folder

Fixes a bug where legacy databases with both unzipped and zipped sources
were incorrectly being loaded with the src folder.

extensions/ql-vscode/src/databases.ts

@@ -121,20 +121,21 @@ async function findDataset(parentDirectory: string): Promise<vscode.Uri> {
   return vscode.Uri.file(dbAbsolutePath);
 }
 
-async function findSourceArchive(
+// exported for testing
+export async function findSourceArchive(
   databasePath: string, silent = false
 ): Promise<vscode.Uri | undefined> {
-
   const relativePaths = ['src', 'output/src_archive'];
 
   for (const relativePath of relativePaths) {
     const basePath = path.join(databasePath, relativePath);
     const zipPath = basePath + '.zip';
 
-    if (await fs.pathExists(basePath)) {
-      return vscode.Uri.file(basePath);
-    } else if (await fs.pathExists(zipPath)) {
+    // Prefer using a zip archive over a directory.
+    if (await fs.pathExists(zipPath)) {
       return encodeArchiveBasePath(zipPath);
+    } else if (await fs.pathExists(basePath)) {
+      return vscode.Uri.file(basePath);
     }
   }
   if (!silent) {
@@ -161,7 +162,6 @@ async function resolveDatabase(
     datasetUri,
     sourceArchiveUri
   };
-
 }
 
 /** Gets the relative paths of all `.dbscheme` files in the given directory. */

extensions/ql-vscode/src/vscode-tests/minimal-workspace/databases.test.ts

@@ -12,7 +12,8 @@ import {
   DatabaseManager,
   DatabaseItemImpl,
   DatabaseContents,
-  FullDatabaseOptions
+  FullDatabaseOptions,
+  findSourceArchive
 } from '../../databases';
 import { Logger } from '../../logging';
 import { QueryServerClient } from '../../queryserver-client';
@@ -179,7 +180,7 @@ describe('databases', () => {
       expect(spy).to.have.been.calledWith(mockEvent);
     });
 
-    it('should add a database item source archive', async function () {
+    it('should add a database item source archive', async function() {
       const mockDbItem = createMockDB();
       mockDbItem.name = 'xxx';
       await (databaseManager as any).addDatabaseSourceArchiveFolder(mockDbItem);
@@ -478,6 +479,49 @@ describe('databases', () => {
       const db = createMockDB(sourceLocationUri(), Uri.file('/path/to/dir/dir.testproj'));
       expect(await db.isAffectedByTest('/path/to/test.ql')).to.false;
     });
+
+  });
+
+  describe.only('findSourceArchive', function() {
+    // not sure why, but some of these tests take more than two second to run.
+    this.timeout(5000);
+
+    ['src', 'output/src_archive'].forEach(name => {
+      it(`should find source folder in ${name}`, async () => {
+        const uri = Uri.file(path.join(dir.name, name));
+        fs.createFileSync(path.join(uri.fsPath, 'hucairz.txt'));
+        const srcUri = await findSourceArchive(dir.name);
+        expect(srcUri!.fsPath).to.eq(uri.fsPath);
+      });
+
+      it(`should find source archive in ${name}.zip`, async () => {
+        const uri = Uri.file(path.join(dir.name, name + '.zip'));
+        fs.createFileSync(uri.fsPath);
+        const srcUri = await findSourceArchive(dir.name);
+        expect(srcUri!.fsPath).to.eq(uri.fsPath);
+      });
+
+      it(`should prioritize ${name}.zip over ${name}`, async () => {
+        const uri = Uri.file(path.join(dir.name, name + '.zip'));
+        fs.createFileSync(uri.fsPath);
+
+        const uriFolder = Uri.file(path.join(dir.name, name));
+        fs.createFileSync(path.join(uriFolder.fsPath, 'hucairz.txt'));
+
+        const srcUri = await findSourceArchive(dir.name);
+        expect(srcUri!.fsPath).to.eq(uri.fsPath);
+      });
+    });
+
+    it('should prioritize src over output/src_archive', async () => {
+      const uriSrc = Uri.file(path.join(dir.name, 'src.zip'));
+      fs.createFileSync(uriSrc.fsPath);
+      const uriSrcArchive = Uri.file(path.join(dir.name, 'src.zip'));
+      fs.createFileSync(uriSrcArchive.fsPath);
+
+      const resultUri = await findSourceArchive(dir.name);
+      expect(resultUri!.fsPath).to.eq(uriSrc.fsPath);
+    });
   });
 
   function createMockDB(