fix: throw precise, actionable error when downloaded deno cli is unusable

packages/edge-bundler/node/bridge.test.ts

@@ -136,3 +136,48 @@ test('Does inherit environment variables if `extendEnv` is not set', async () =>
 
   await rm(tmpDir.path, { force: true, recursive: true, maxRetries: 10 })
 })
+
+test('Provides actionable error message when downloaded binary cannot be executed', async () => {
+  const tmpDir = await tmp.dir()
+  const latestVersion = semver.minVersion(DENO_VERSION_RANGE)?.version ?? ''
+  const data = new PassThrough()
+  const archive = archiver('zip', { zlib: { level: 9 } })
+
+  archive.pipe(data)
+  // Create a binary that will fail to execute (invalid content)
+  archive.append(Buffer.from('invalid binary content'), {
+    name: platform === 'win32' ? 'deno.exe' : 'deno',
+  })
+  archive.finalize()
+
+  const target = getPlatformTarget()
+
+  nock('https://dl.deno.land').get('/release-latest.txt').reply(200, `v${latestVersion}`)
+  nock('https://dl.deno.land')
+    .get(`/release/v${latestVersion}/deno-${target}.zip`)
+    .reply(200, () => data)
+
+  const deno = new DenoBridge({
+    cacheDirectory: tmpDir.path,
+    useGlobal: false,
+  })
+
+  try {
+    await deno.getBinaryPath()
+    expect.fail('Should have thrown an error')
+  } catch (error) {
+    expect(error).toBeInstanceOf(Error)
+    const errorMessage = (error as Error).message
+
+    expect(errorMessage).toContain('Failed to set up Deno for Edge Functions')
+    expect(errorMessage).toMatch(/Error:/)
+    expect(errorMessage).toMatch(/Downloaded to: .+deno(\.exe)?/)
+    expect(errorMessage).toContain(tmpDir.path)
+    expect(errorMessage).toMatch(/Platform: (darwin|linux|win32)\/(x64|arm64|ia32)/)
+    expect(errorMessage).toContain('This may be caused by permissions, antivirus software, or platform incompatibility')
+    expect(errorMessage).toContain('Try clearing the Deno cache directory and retrying')
+    expect(errorMessage).toContain('https://ntl.fyi/install-deno')
+  }
+
+  await rm(tmpDir.path, { force: true, recursive: true, maxRetries: 10 })
+})

packages/edge-bundler/node/bridge.ts

@@ -84,14 +84,24 @@ export class DenoBridge {
     this.logger.system(`Downloading Deno CLI to ${this.cacheDirectory}`)
 
     const binaryPath = await download(this.cacheDirectory, this.versionRange, this.logger)
-    const downloadedVersion = await this.getBinaryVersion(binaryPath)
+    const result = await this.getBinaryVersion(binaryPath)
 
-    // We should never get here, because it means that `DENO_VERSION_RANGE` is
-    // a malformed semver range. If this does happen, let's throw an error so
-    // that the tests catch it.
-    if (downloadedVersion === undefined) {
+    // If we can't execute the downloaded binary, provide actionable info to diagnose and self-heal if possible
+    if (result.error) {
       const error = new Error(
-        'There was a problem setting up the Edge Functions environment. To try a manual installation, visit https://ntl.fyi/install-deno.',
+        `Failed to set up Deno for Edge Functions.
+Error: ${result.error.message}
+Downloaded to: ${binaryPath}
+Platform: ${process.platform}/${process.arch}
+
+This may be caused by permissions, antivirus software, or platform incompatibility.
+
+Try clearing the Deno cache directory and retrying:
+  ${this.cacheDirectory}
+
+Supported Deno versions: ${this.versionRange}
+
+To install Deno manually: https://ntl.fyi/install-deno`,
       )
 
       await this.onAfterDownload?.(error)
@@ -101,26 +111,29 @@ export class DenoBridge {
       throw error
     }
 
-    await this.writeVersionFile(downloadedVersion)
+    await this.writeVersionFile(result.version)
 
     await this.onAfterDownload?.()
 
     return binaryPath
   }
 
-  async getBinaryVersion(binaryPath: string) {
+  async getBinaryVersion(
+    binaryPath: string,
+  ): Promise<{ version: string; error?: undefined } | { version?: undefined; error: Error }> {
     try {
       const { stdout } = await execa(binaryPath, ['--version'])
       const version = stdout.match(/^deno ([\d.]+)/)
 
       if (!version) {
         this.logger.system(`getBinaryVersion no version found. binaryPath ${binaryPath}`)
-        return
+        return { error: new Error('Could not parse Deno version from output') }
       }
 
-      return version[1]
+      return { version: version[1] }
     } catch (error) {
       this.logger.system('getBinaryVersion failed', error)
+      return { error: error instanceof Error ? error : new Error(String(error)) }
     }
   }
 
@@ -152,11 +165,11 @@ export class DenoBridge {
     }
 
     const globalBinaryName = 'deno'
-    const globalVersion = await this.getBinaryVersion(globalBinaryName)
+    const result = await this.getBinaryVersion(globalBinaryName)
 
-    if (globalVersion === undefined || !semver.satisfies(globalVersion, this.versionRange)) {
+    if (result.error || !semver.satisfies(result.version, this.versionRange)) {
       this.logger.system(
-        `No globalVersion or semver not satisfied. globalVersion: ${globalVersion}, versionRange: ${this.versionRange}`,
+        `No globalVersion or semver not satisfied. globalVersion: ${result.version}, versionRange: ${this.versionRange}`,
       )
       return
     }

packages/edge-bundler/node/config.ts

@@ -96,7 +96,8 @@ export const getFunctionConfig = async ({
   const collector = await tmp.file()
 
   // Retrieving the version of Deno.
-  const version = new SemVer((await deno.getBinaryVersion((await deno.getBinaryPath({ silent: true })).path)) || '')
+  const result = await deno.getBinaryVersion((await deno.getBinaryPath({ silent: true })).path)
+  const version = new SemVer(result.version || '')
 
   // The extractor will use its exit code to signal different error scenarios,
   // based on the list of exit codes we send as an argument. We then capture