Update transform mode for API changes made in PR #40

Author: aomarks

README.md

@@ -21,11 +21,16 @@ The `lit-localize` module exports the following functions:
 Set configuration parameters for lit-localize when in runtime mode. Returns an
 object with functions:
 
-- [`getLocale`](#getLocale): Return the active locale code.
-- [`setLocale`](#setLocale): Set the active locale code.
+- [`getLocale`](#getlocale-string): Return the active locale code.
+- [`setLocale`](#setlocalelocale-string-promise): Set the active locale code.
 
 Throws if called more than once.
 
+When in transform mode, the lit-localize CLI will error if this function is
+called. Use
+[`configureTransformLocalization`](#configuretransformlocalizationconfiguration)
+instead.
+
 The `configuration` object must have the following properties:
 
 - `sourceLocale: string`: Required locale code in which source templates in this
@@ -52,12 +57,13 @@ const {getLocale, setLocale} = configureLocalization({
 ### `configureTransformLocalization(configuration)`
 
 Set configuration parameters for lit-localize when in transform mode. Returns an
-object with functions:
+object with function:
 
-- [`getLocale`](#getLocale): Return the active locale code.
+- [`getLocale`](#getlocale-string): Return the active locale code.
 
-(Note that [`setLocale`](#setLocale) is not available, because changing locales
-at runtime is not supported in transform mode.)
+(Note that [`setLocale`](#setlocalelocale-string-promise) is not available from
+this function, because changing locales at runtime is not supported in transform
+mode.)
 
 Throws if called more than once.
 
@@ -74,14 +80,19 @@ const {getLocale} = configureLocalization({
 });
 ```
 
+In transform mode, calls to this function are transformed to an object with a
+`getLocale` implementation that returns the static locale code for each locale
+bundle. For example:
+
+```typescript
+const {getLocale} = {getLocale: () => 'es-419'};
+```
+
 ### `getLocale(): string`
 
 Return the active locale code.
 
-In transform mode, calls to this function are transformed into the static locale
-code string for each emitted locale.
-
-### `setLocale(locale: string)`
+### `setLocale(locale: string): Promise`
 
 Set the active locale code, and begin loading templates for that locale using
 the `loadLocale` function that was passed to `configureLocalization`. Returns a

src/outputters/transform.ts

@@ -118,29 +118,40 @@ class Transformer {
       return undefined;
     }
 
-    // configureLocalization(...) -> undefined
+    // configureTransformLocalization(...) -> {getLocale: () => "es-419"}
     if (
-      this.isCallToTaggedFunction(node, '_LIT_LOCALIZE_CONFIGURE_LOCALIZATION_')
+      this.isCallToTaggedFunction(
+        node,
+        '_LIT_LOCALIZE_CONFIGURE_TRANSFORM_LOCALIZATION_'
+      )
     ) {
-      return ts.createIdentifier('undefined');
-    }
-
-    // getLocale() -> "es-419"
-    if (this.isCallToTaggedFunction(node, '_LIT_LOCALIZE_GET_LOCALE_')) {
-      return ts.createStringLiteral(this.locale);
-    }
-
-    // setLocale("es-419") -> undefined
-    if (this.isCallToTaggedFunction(node, '_LIT_LOCALIZE_SET_LOCALE_')) {
-      return ts.createIdentifier('undefined');
+      return ts.createObjectLiteral(
+        [
+          ts.createPropertyAssignment(
+            ts.createIdentifier('getLocale'),
+            ts.createArrowFunction(
+              undefined,
+              undefined,
+              [],
+              undefined,
+              ts.createToken(ts.SyntaxKind.EqualsGreaterThanToken),
+              ts.createStringLiteral(this.locale)
+            )
+          ),
+        ],
+        false
+      );
     }
 
-    // localeReady() -> Promise.resolve(undefined)
-    if (this.isCallToTaggedFunction(node, '_LIT_LOCALIZE_LOCALE_READY_')) {
-      return ts.createCall(
-        ts.createPropertyAccess(ts.createIdentifier('Promise'), 'resolve'),
-        [],
-        [ts.createIdentifier('undefined')]
+    // configureLocalization(...) -> Error
+    if (
+      this.isCallToTaggedFunction(node, '_LIT_LOCALIZE_CONFIGURE_LOCALIZATION_')
+    ) {
+      // TODO(aomarks) This error is not surfaced earlier in the analysis phase
+      // as a nicely formatted diagnostic, but it should be.
+      throw new KnownError(
+        'Cannot use configureLocalization in transform mode. ' +
+          'Use configureTransformLocalization instead.'
       );
     }
 

src/tests/transform.unit.test.ts

@@ -334,51 +334,34 @@ test('exclude different msg function', (t) => {
   );
 });
 
-test('configureLocalization() -> undefined', (t) => {
+test('configureTransformLocalization() -> {getLocale: () => "es-419"}', (t) => {
   checkTransform(
     t,
-    `import {configureLocalization} from './lib_client/index.js';
-     configureLocalization({
+    `import {configureTransformLocalization} from './lib_client/index.js';
+     const {getLocale} = configureTransformLocalization({
        sourceLocale: 'en',
-       targetLocales: ['es-419'],
-       loadLocale: (locale: string) => import(\`/\${locale}.js\`),
-     });`,
-    `undefined;`
-  );
-});
-
-test('getLocale() -> "es-419"', (t) => {
-  checkTransform(
-    t,
-    `import {getLocale} from './lib_client/index.js';
-     getLocale();`,
-    `"en";`,
-    {locale: 'es-419'}
-  );
-
-  checkTransform(
-    t,
-    `import {getLocale} from './lib_client/index.js';
-     getLocale();`,
-    `"es-419";`,
+     });
+     const locale = getLocale();`,
+    `const {getLocale} = {getLocale: () => 'es-419'};
+     const locale = getLocale();`,
     {locale: 'es-419'}
   );
 });
 
-test('setLocale() -> undefined', (t) => {
-  checkTransform(
-    t,
-    `import {setLocale} from './lib_client/index.js';
-     setLocale("es-419");`,
-    `undefined;`
-  );
-});
-
-test('localeReady() -> Promise.resolve(undefined)', (t) => {
-  checkTransform(
-    t,
-    `import {localeReady} from './lib_client/index.js';
-     localeReady().then(() => console.log('ok'))`,
-    `Promise.resolve(undefined).then(() => console.log('ok'))`
+test('configureLocalization() throws', (t) => {
+  t.throws(
+    () =>
+      checkTransform(
+        t,
+        `import {configureLocalization} from './lib_client/index.js';
+     configureLocalization({
+       sourceLocale: 'en',
+       targetLocales: ['es-419'],
+       loadLocale: (locale: string) => import(\`/\${locale}.js\`),
+     });`,
+        `undefined;`
+      ),
+    undefined,
+    'Cannot use configureLocalization in transform mode'
   );
 });

src_client/index.ts

@@ -111,7 +111,9 @@ let loading = new Deferred<void>();
  *
  * Throws if called more than once.
  */
-export const configureLocalization: ((config: RuntimeConfiguration) => void) & {
+export const configureLocalization: ((
+  config: RuntimeConfiguration
+) => {getLocale: typeof getLocale; setLocale: typeof setLocale}) & {
   _LIT_LOCALIZE_CONFIGURE_LOCALIZATION_?: never;
 } = (config: RuntimeConfiguration) => {
   if (configured === true) {
@@ -133,14 +135,18 @@ export const configureLocalization: ((config: RuntimeConfiguration) => void) & {
  *
  * Throws if called more than once.
  */
-export function configureTransformLocalization(config: TransformConfiguration) {
+export const configureTransformLocalization: ((
+  config: TransformConfiguration
+) => {getLocale: typeof getLocale}) & {
+  _LIT_LOCALIZE_CONFIGURE_TRANSFORM_LOCALIZATION_?: never;
+} = (config: TransformConfiguration) => {
   if (configured === true) {
     throw new Error('lit-localize can only be configured once');
   }
   configured = true;
   activeLocale = sourceLocale = config.sourceLocale;
   return {getLocale};
-}
+};
 
 /**
  * Return the active locale code.

testdata/transform/goldens/foo.ts

@@ -1,5 +1,11 @@
 import {html} from 'lit-html';
-import {msg} from '../../../lib_client/index.js';
+import {
+  msg,
+  configureTransformLocalization,
+} from '../../../lib_client/index.js';
+
+const {getLocale} = configureTransformLocalization({sourceLocale: 'en'});
+console.log(`Locale is ${getLocale()}`);
 
 msg('string', 'Hello World!');
 

testdata/transform/goldens/tsout/en/foo.js

@@ -1,4 +1,6 @@
 import {html} from 'lit-html';
+const {getLocale} = {getLocale: () => 'en'};
+console.log(`Locale is ${getLocale()}`);
 ('Hello World!');
 html`Hello <b><i>World!</i></b>`;
 `Hello World!`;

testdata/transform/goldens/tsout/es-419/foo.js

@@ -1,4 +1,6 @@
 import {html} from 'lit-html';
+const {getLocale} = {getLocale: () => 'es-419'};
+console.log(`Locale is ${getLocale()}`);
 `Hola Mundo!`;
 html`Hola <b><i>Mundo!</i></b>`;
 `Hola World!`;

testdata/transform/goldens/tsout/zh_CN/foo.js

@@ -1,4 +1,6 @@
 import {html} from 'lit-html';
+const {getLocale} = {getLocale: () => 'zh_CN'};
+console.log(`Locale is ${getLocale()}`);
 `\u4F60\u597D\uFF0C\u4E16\u754C\uFF01`;
 html`你好, <b><i>世界!</i></b>`;
 `Hello World!`;

testdata/transform/input/foo.ts

@@ -1,5 +1,11 @@
 import {html} from 'lit-html';
-import {msg} from '../../../lib_client/index.js';
+import {
+  msg,
+  configureTransformLocalization,
+} from '../../../lib_client/index.js';
+
+const {getLocale} = configureTransformLocalization({sourceLocale: 'en'});
+console.log(`Locale is ${getLocale()}`);
 
 msg('string', 'Hello World!');