fix(cli): accept capacitor.config.js as a --capacitor-config target

cli/src/capacitor-cli.ts

@@ -13,6 +13,8 @@ import type { CapacitorConfig } from './schemas/config'
 import { loadConfig as loadConfigUntyped, writeConfig as writeConfigUntyped } from '@capacitor/cli/dist/config'
 // @ts-expect-error `@capacitor/cli/dist/util/monorepotools` ships no type declarations
 import { findMonorepoRoot as findMonorepoRootUntyped, findNXMonorepoRoot as findNXMonorepoRootUntyped, isMonorepo as isMonorepoUntyped, isNXMonorepo as isNXMonorepoUntyped } from '@capacitor/cli/dist/util/monorepotools'
+// @ts-expect-error `@capacitor/cli/dist/util/js` ships no type declarations
+import { formatJSObject as formatJSObjectUntyped } from '@capacitor/cli/dist/util/js'
 // @ts-expect-error `@capacitor/cli/dist/util/node` ships no type declarations
 import { requireTS as requireTSUntyped } from '@capacitor/cli/dist/util/node'
 
@@ -24,6 +26,9 @@ export interface CapacitorCliConfig {
 }
 
 export const requireTS: (typescript: unknown, filePath: string) => Record<string, unknown> = requireTSUntyped
+// Serializes a config object the way Capacitor formats its own `.ts` writes, so
+// the `.js` config we emit reads identically to the `.ts` one Capacitor produces.
+export const formatJSObject: (value: unknown) => string = formatJSObjectUntyped
 export const loadConfig: () => Promise<CapacitorCliConfig> = loadConfigUntyped
 export const writeConfig: (extConfig: CapacitorConfig, extConfigFilePath: string) => Promise<void> = writeConfigUntyped
 export const findMonorepoRoot: (currentPath: string) => string = findMonorepoRootUntyped

cli/src/config/index.ts

@@ -1,17 +1,21 @@
 import { AsyncLocalStorage } from 'node:async_hooks'
 import { existsSync, realpathSync, statSync } from 'node:fs'
-import { readFile } from 'node:fs/promises'
+import { readFile, writeFile } from 'node:fs/promises'
 import { createRequire } from 'node:module'
 import { basename, extname, isAbsolute, relative, resolve, sep } from 'node:path'
 import { cwd } from 'node:process'
 import type { CapacitorConfig, ExtConfigPairs } from '../schemas/config'
-import { loadConfig as loadConfigCap, requireTS, writeConfig as writeConfigCap } from '../capacitor-cli'
+import { formatJSObject, loadConfig as loadConfigCap, requireTS, writeConfig as writeConfigCap } from '../capacitor-cli'
 
 export type { CapacitorConfig, ExtConfigPairs } from '../schemas/config'
 
 let configWriteTarget: string | undefined
 const configWriteTargetStore = new AsyncLocalStorage<{ filePath: string | undefined }>()
-const capacitorConfigFilePattern = /^capacitor\.config(?:\.[^.]+)*\.(?:ts|json)$/
+// `.js` is accepted alongside `.ts`/`.json` — these are the three config names Capacitor's
+// own loader recognizes (see `capacitorConfigFiles` in init/command.ts). `.mjs`/`.cjs` are
+// intentionally excluded: Capacitor never loads them as configs, and the `.js` writer below
+// emits CommonJS, so allowing them would let reads pass but writes silently no-op.
+const capacitorConfigFilePattern = /^capacitor\.config(?:\.[^.]+)*\.(?:ts|js|json)$/
 
 /**
  * Overrides the config file Capacitor writes after loading the active root config.
@@ -45,7 +49,7 @@ export function resolveCapacitorConfigTargetPath(value: string | undefined, init
   if (!existsSync(resolved) || !statSync(resolved).isFile())
     throw new Error(`Capacitor config path does not exist: ${resolved}`)
   if (!capacitorConfigFilePattern.test(basename(resolved)))
-    throw new Error(`Capacitor config path must point to a capacitor.config.*.ts or capacitor.config.*.json file: ${resolved}`)
+    throw new Error(`Capacitor config path must point to a capacitor.config.*.ts, capacitor.config.*.js, or capacitor.config.*.json file: ${resolved}`)
 
   const workspaceRoot = realpathSync(initialCwd)
   const target = realpathSync(resolved)
@@ -59,11 +63,32 @@ async function loadConfigTarget(filePath: string): Promise<CapacitorConfig> {
   if (extname(filePath) === '.json')
     return JSON.parse(await readFile(filePath, 'utf8')) as CapacitorConfig
 
-  const configModule = requireTS(createRequire(filePath)('typescript'), filePath)
+  // Mirror Capacitor's own `capacitor.config.js` loader, which simply `require()`s the file.
+  const configModule = extname(filePath) === '.js'
+    ? (createRequire(filePath)(filePath) as Record<string, unknown>)
+    : requireTS(createRequire(filePath)('typescript'), filePath)
   const exportedConfig = configModule.default ?? configModule
   return (typeof exportedConfig === 'function' ? await exportedConfig() : await exportedConfig) as CapacitorConfig
 }
 
+/**
+ * Persists a config update to the target file. Capacitor's own `writeConfig`
+ * silently no-ops on `.js` (it only formats `.ts`/`.json`), so we format and
+ * write `capacitor.config.js` ourselves — mirroring how Capacitor emits `.ts`.
+ */
+async function writeConfigTarget(extConfig: CapacitorConfig, filePath: string): Promise<void> {
+  if (extname(filePath) === '.js') {
+    const source = `/** @type {import('@capacitor/cli').CapacitorConfig} */
+const config = ${formatJSObject(extConfig)}
+
+module.exports = config
+`
+    await writeFile(filePath, source)
+    return
+  }
+  await writeConfigCap(extConfig, filePath)
+}
+
 export async function loadConfig(): Promise<ExtConfigPairs | undefined> {
   const config = await loadConfigCap()
   return {
@@ -107,7 +132,7 @@ export async function writeConfig(key: string, config: ExtConfigPairs, raw = fal
       extConfig.plugins[key] = config.config.plugins?.[key]
     else
       extConfig = config.config
-    await writeConfigCap(extConfig, oldConfig.path)
+    await writeConfigTarget(extConfig, oldConfig.path)
   }
 }
 

cli/test/test-capacitor-config-target.mjs

@@ -75,6 +75,24 @@ try {
   appName: 'Factory app',
   webDir: 'factory-www',
 })
+`
+  const javascriptConfigSource = `/** @type {import('@capacitor/cli').CapacitorConfig} */
+const config = {
+  appId: 'com.example.javascript',
+  appName: 'JavaScript app',
+  webDir: 'javascript-www',
+  plugins: {
+    JsOnlyPlugin: {
+      enabled: true,
+    },
+    CapacitorUpdater: {
+      appId: 'com.example.javascript',
+      jsOnly: true,
+    },
+  },
+}
+
+module.exports = config
 `
   const appDir = join(root, 'apps', 'qr-code-reader')
   mkdirSync(configDir, { recursive: true })
@@ -86,14 +104,16 @@ try {
   writeFileSync(multiPartConfigTarget, 'export default {}\n')
   writeFileSync(configTarget, configTargetSource)
   writeFileSync(jsonConfigTarget, JSON.stringify({ appId: 'com.example.json', appName: 'JSON app', webDir: 'json-www' }))
-  writeFileSync(javascriptConfigTarget, 'module.exports = {}\n')
+  writeFileSync(javascriptConfigTarget, javascriptConfigSource)
   writeFileSync(factoryConfigTarget, factoryConfigSource)
   writeFileSync(join(configDir, 'not-a-capacitor-config.ts'), 'export default {}\n')
+  writeFileSync(join(configDir, 'capacitor.config.esm.mjs'), 'export default {}\n')
   writeFileSync(outsideConfigTarget, 'export default {}\n')
   assert.equal(resolveCapacitorConfigTargetPath('./env-configs/capacitor.config.qr-code-reader.production.ts', root), multiPartConfigTarget)
   assert.equal(resolveCapacitorConfigTargetPath('./env-configs/capacitor.config.qr-code-reader.ts', root), configTarget)
   assert.equal(resolveCapacitorConfigTargetPath('./env-configs/capacitor.config.json-target.json', root), jsonConfigTarget)
-  assert.throws(() => resolveCapacitorConfigTargetPath('./env-configs/capacitor.config.javascript.js', root), /\.ts or capacitor\.config\.\*\.json/)
+  assert.equal(resolveCapacitorConfigTargetPath('./env-configs/capacitor.config.javascript.js', root), javascriptConfigTarget)
+  assert.throws(() => resolveCapacitorConfigTargetPath('./env-configs/capacitor.config.esm.mjs', root), /\.ts, capacitor\.config\.\*\.js, or capacitor\.config\.\*\.json/)
   assert.throws(() => resolveCapacitorConfigTargetPath(relative(root, outsideConfigTarget), root), /must stay within the current working directory/)
   assert.throws(() => resolveCapacitorConfigTargetPath(outsideConfigTarget, root), /must stay within the current working directory/)
   const outsideLink = join(root, 'outside-link')
@@ -110,6 +130,11 @@ try {
     const factoryConfigWriteSnapshot = await loadConfigForWrite()
     assert.equal(factoryConfigWriteSnapshot.config.appId, 'com.example.factory')
     assert.equal(factoryConfigWriteSnapshot.config.webDir, 'factory-www')
+    setConfigWriteTarget(javascriptConfigTarget)
+    const javascriptConfigWriteSnapshot = await loadConfigForWrite()
+    assert.equal(javascriptConfigWriteSnapshot.config.appId, 'com.example.javascript')
+    assert.equal(javascriptConfigWriteSnapshot.config.webDir, 'javascript-www')
+    assert.equal(javascriptConfigWriteSnapshot.config.plugins.CapacitorUpdater.jsOnly, true)
     setConfigWriteTarget(jsonConfigTarget)
     const jsonConfigSnapshot = await getConfig()
     assert.equal(jsonConfigSnapshot.config.appId, 'com.example.root')
@@ -191,6 +216,34 @@ try {
   assert.doesNotMatch(writtenTargetConfig, /RootOnlyPlugin/)
   assert.equal(readFileSync(rootConfig, 'utf8'), rootConfigSource)
 
+  // Capacitor's own writeConfig silently no-ops on `.js`, so exercise a real write
+  // through the CLI and confirm the `capacitor.config.js` target is actually updated.
+  const javascriptCommand = spawnSync('node', [
+    join(cliRoot, 'dist/index.js'),
+    'app',
+    'setting',
+    'plugins.CapacitorUpdater.autoUpdate',
+    '--bool',
+    'false',
+    '--capacitor-config',
+    javascriptConfigTarget,
+  ], {
+    cwd: root,
+    encoding: 'utf8',
+    env: { ...process.env, CAPGO_DISABLE_TELEMETRY: 'true' },
+  })
+
+  assert.equal(javascriptCommand.status, 0, `${javascriptCommand.stdout}\n${javascriptCommand.stderr}`)
+  const writtenJavascriptConfig = readFileSync(javascriptConfigTarget, 'utf8')
+  assert.match(writtenJavascriptConfig, /module\.exports = config/)
+  assert.match(writtenJavascriptConfig, /appId:\s*'com\.example\.javascript'/)
+  assert.match(writtenJavascriptConfig, /webDir:\s*'javascript-www'/)
+  assert.match(writtenJavascriptConfig, /JsOnlyPlugin/)
+  assert.match(writtenJavascriptConfig, /jsOnly:\s*true/)
+  assert.match(writtenJavascriptConfig, /autoUpdate:\s*false/)
+  assert.doesNotMatch(writtenJavascriptConfig, /RootOnlyPlugin/)
+  assert.equal(readFileSync(rootConfig, 'utf8'), rootConfigSource)
+
   const notificationHelper = join(root, 'src', 'capgo-notifications.ts')
   const notificationsCommand = spawnSync('node', [
     join(cliRoot, 'dist/index.js'),