Back up code-server directory when updating

Author: code-asher

src/node/app/update.ts

@@ -221,8 +221,13 @@ export class UpdateHttpProvider extends HttpProvider {
         targetPath = path.resolve(__dirname, "../../../")
       }
 
-      logger.debug("Replacing files", field("target", targetPath))
-      await fs.move(directoryPath, targetPath, { overwrite: true })
+      // Move the old directory to prevent potential data loss.
+      const backupPath = path.resolve(targetPath, `../${path.basename(targetPath)}.${Date.now().toString()}`)
+      logger.debug("Replacing files", field("target", targetPath), field("backup", backupPath))
+      await fs.move(targetPath, backupPath)
+
+      // Move the new directory.
+      await fs.move(directoryPath, targetPath)
 
       await fs.remove(downloadPath)
 

test/update.test.ts

@@ -214,13 +214,18 @@ describe("update", () => {
     await p.downloadAndApplyUpdate(update, destination)
     assert.equal(`console.log("UPDATED")`, await fs.readFile(entry, "utf8"))
 
-    // Should still work if there is no existing version somehow.
-    await fs.remove(destination)
-    await p.downloadAndApplyUpdate(update, destination)
-    assert.equal(`console.log("UPDATED")`, await fs.readFile(entry, "utf8"))
+    // There should be a backup.
+    const dir = (await fs.readdir(path.join(tmpdir, "tests/updates"))).filter((dir) => {
+      return dir.startsWith("code-server.")
+    })
+    assert.equal(dir.length, 1)
+    assert.equal(
+      `console.log("OLD")`,
+      await fs.readFile(path.join(tmpdir, "tests/updates", dir[0], "code-server"), "utf8"),
+    )
 
     const archiveName = await p.getReleaseName(update)
-    assert.deepEqual(spy, ["/latest", `/download/${version}/${archiveName}`, `/download/${version}/${archiveName}`])
+    assert.deepEqual(spy, ["/latest", `/download/${version}/${archiveName}`])
   })
 
   it("should not reject if unable to fetch", async () => {