Add mapContextAsync

.babelrc

@@ -1,4 +1,7 @@
 {
+    "presets": [
+        "stage-3"
+    ],
     "plugins": [
         "babel-plugin-transform-es2015-modules-commonjs"
     ]

bundle_config.js

@@ -0,0 +1,14 @@
+import acornAsyncIteration from 'acorn-async-iteration/inject';
+
+export default {
+  output: {
+    format: 'umd'
+  },
+  acorn: {
+    ecmaVersion: 9,
+    plugins: { asyncIteration: true }
+  },
+  acornInjectPlugins: [
+    acornAsyncIteration
+  ]
+};

common.mk

@@ -23,10 +23,12 @@ test:
 ifneq (,$(wildcard ./test/__setup.js))
 	@mocha --recursive --ui tdd \
 	    --require babel-register \
+	    --require babel-polyfill \
 	    --require ./test/__setup
 else
 	@mocha --recursive --ui tdd \
-	    --require babel-register
+	    --require babel-register \
+	    --require babel-polyfill
 endif
 
 html: $(SOURCES)

compat_config.js

@@ -1,10 +1,14 @@
 import babel from 'rollup-plugin-babel';
 
 export default {
+  output: {
+    format: 'umd'
+  },
   plugins: [
     babel({
       'babelrc': false,
       'presets': [
+        'stage-3',
         ['env', {
           // Cf. https://github.com/rollup/rollup-plugin-babel#modules
           'modules': false,

eslint_src.json

@@ -1,6 +1,7 @@
 {
+    "parser": "babel-eslint",
     "parserOptions": {
-        "ecmaVersion": 8,
+        "ecmaVersion": 9,
         "sourceType": "module"
     },
     "env": {

eslint_test.json

@@ -1,6 +1,7 @@
 {
+    "parser": "babel-eslint",
     "parserOptions": {
-        "ecmaVersion": 8,
+        "ecmaVersion": 9,
         "sourceType": "module",
         "ecmaFeatures": {
             "jsx": true

fluent-dom/makefile

@@ -7,7 +7,7 @@ build: $(PACKAGE).js compat.js
 
 $(PACKAGE).js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
-		--output.format umd \
+		--config $(ROOT)/bundle_config.js \
 		--banner "/* $(PACKAGE)@$(VERSION) */" \
 		--amd.id $(PACKAGE) \
 		--name $(GLOBAL) \
@@ -17,7 +17,6 @@ $(PACKAGE).js: $(SOURCES)
 compat.js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
 		--config $(ROOT)/compat_config.js \
-		--output.format umd \
 		--banner "/* $(PACKAGE)@$(VERSION) */" \
 		--amd.id $(PACKAGE) \
 		--name $(GLOBAL) \

fluent-gecko/xpcom_config.js

@@ -1,6 +1,8 @@
+import bundleConfig from '../bundle_config';
+
 const version = require('../fluent/package.json').version;
 
-export default {
+export default Object.assign({}, bundleConfig, {
   preferConst: true,
   context: 'this',
   output: {
@@ -23,4 +25,4 @@ export default {
  */\n\n`,
     intro: `/* fluent@${version} */`,
   }
-};
+});

fluent-gecko/xpcom_dom_config.js

@@ -1,8 +1,9 @@
 import { resolve } from 'path';
+import bundleConfig from '../bundle_config';
 
 const version = require('../fluent/package.json').version;
 
-export default {
+export default Object.assign({}, bundleConfig, {
   external: [
     resolve('../fluent-dom/src/localization.js')
   ],
@@ -28,4 +29,4 @@ export default {
   },
   preferConst: true,
   context: 'this'
-};
+});

fluent-intl-polyfill/bundle_config.js

@@ -1,9 +1,10 @@
+import bundleConfig from '../bundle_config';
 import nodeResolve from 'rollup-plugin-node-resolve';
 
-export default {
+export default Object.assign({}, bundleConfig, {
   context: 'this',
   plugins: [
     nodeResolve(),
   ]
-};
+});
 

fluent-intl-polyfill/compat_config.js

@@ -1,23 +1,11 @@
+import compatConfig from '../compat_config';
 import nodeResolve from 'rollup-plugin-node-resolve';
 import babel from 'rollup-plugin-babel';
 
-export default {
+export default Object.assign({}, compatConfig, {
   context: 'this',
   plugins: [
     nodeResolve(),
-    babel({
-      'babelrc': false,
-      'presets': [
-        ['env', {
-          'modules': false
-        }]
-      ],
-      'plugins': [
-        'external-helpers',
-        ['babel-plugin-transform-builtin-extend', {
-          globals: ['Error']
-        }]
-      ]
-    }),
+    ...compatConfig.plugins
   ],
-};
+});

fluent-intl-polyfill/makefile

@@ -7,18 +7,16 @@ build: $(PACKAGE).js compat.js
 
 $(PACKAGE).js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
-	    --output.format umd \
+	    --config $(CURDIR)/bundle_config.js \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \
-	    --config $(CURDIR)/bundle_config.js \
 	    --output.file $@
 	@echo -e " $(OK) $@ built"
 
 compat.js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
 	    --config $(CURDIR)/compat_config.js \
-	    --output.format umd \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \

fluent-langneg/makefile

@@ -7,7 +7,7 @@ build: $(PACKAGE).js compat.js
 
 $(PACKAGE).js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
-	    --output.format umd \
+	    --config $(ROOT)/bundle_config.js \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \
@@ -17,7 +17,6 @@ $(PACKAGE).js: $(SOURCES)
 compat.js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
 	    --config $(ROOT)/compat_config.js \
-	    --output.format umd \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \

fluent-react/makefile

@@ -8,7 +8,7 @@ build: $(PACKAGE).js compat.js
 
 $(PACKAGE).js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
-	    --output.format umd \
+	    --config $(ROOT)/bundle_config.js \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \
@@ -19,7 +19,6 @@ $(PACKAGE).js: $(SOURCES)
 compat.js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
 	    --config $(ROOT)/compat_config.js \
-	    --output.format umd \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \

fluent-syntax/makefile

@@ -7,7 +7,7 @@ build: $(PACKAGE).js compat.js
 
 $(PACKAGE).js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
-	    --output.format umd \
+	    --config $(ROOT)/bundle_config.js \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \
@@ -17,7 +17,6 @@ $(PACKAGE).js: $(SOURCES)
 compat.js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
 	    --config $(ROOT)/compat_config.js \
-	    --output.format umd \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \

fluent-web/bundle_config.js

@@ -1,8 +1,12 @@
+import bundleConfig from '../bundle_config';
 import nodeResolve from 'rollup-plugin-node-resolve';
 
-export default {
+export default Object.assign({}, bundleConfig, {
+  output: {
+    format: 'iife'
+  },
   context: 'this',
   plugins: [
     nodeResolve(),
   ]
-};
+});

fluent-web/compat_config.js

@@ -1,23 +1,11 @@
+import compatConfig from '../compat_config';
 import nodeResolve from 'rollup-plugin-node-resolve';
 import babel from 'rollup-plugin-babel';
 
-export default {
+export default Object.assign({}, compatConfig, {
   context: 'this',
   plugins: [
     nodeResolve(),
-    babel({
-      'babelrc': false,
-      'presets': [
-        ['env', {
-          'modules': false
-        }]
-      ],
-      'plugins': [
-        'external-helpers',
-        ['babel-plugin-transform-builtin-extend', {
-          globals: ['Error']
-        }]
-      ]
-    }),
+    ...compatConfig.plugins
   ],
-};
+});

fluent-web/makefile

@@ -7,18 +7,16 @@ build: $(PACKAGE).js compat.js
 
 $(PACKAGE).js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
-		--output.format iife \
+		--config $(CURDIR)/bundle_config.js \
 		--banner "/* $(PACKAGE)@$(VERSION) */" \
 		--amd.id $(PACKAGE) \
 		--name $(GLOBAL) \
-		--config $(CURDIR)/bundle_config.js \
 		--output.file $@
 	@echo -e " $(OK) $@ built"
 
 compat.js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
 		--config $(CURDIR)/compat_config.js \
-		--output.format umd \
 		--banner "/* $(PACKAGE)@$(VERSION) */" \
 		--amd.id $(PACKAGE) \
 		--name $(GLOBAL) \

fluent/makefile

@@ -7,7 +7,7 @@ build: $(PACKAGE).js compat.js
 
 $(PACKAGE).js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
-	    --output.format umd \
+	    --config $(ROOT)/bundle_config.js \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \
@@ -17,7 +17,6 @@ $(PACKAGE).js: $(SOURCES)
 compat.js: $(SOURCES)
 	@rollup $(CURDIR)/src/index.js \
 	    --config $(ROOT)/compat_config.js \
-	    --output.format umd \
 	    --banner "/* $(PACKAGE)@$(VERSION) */" \
 	    --amd.id $(PACKAGE) \
 	    --name $(GLOBAL) \

fluent/src/fallback.js

@@ -48,7 +48,6 @@
  * @param {string|Array<string>} ids
  * @returns {MessageContext|Array<MessageContext>}
  */
-
 export function mapContextSync(iterable, ids) {
   if (!Array.isArray(ids)) {
     return getContextForId(iterable, ids);
@@ -71,3 +70,43 @@ function getContextForId(iterable, id) {
 
   return null;
 }
+
+/*
+ * Asynchronously map an identifier or an array of identifiers to the best
+ * `MessageContext` instance(s).
+ *
+ * @param {AsyncIterable} iterable
+ * @param {string|Array<string>} ids
+ * @returns {Promise<MessageContext|Array<MessageContext>>}
+ */
+export async function mapContextAsync(iterable, ids) {
+  if (!Array.isArray(ids)) {
+    for await (const context of iterable) {
+      if (context.hasMessage(ids)) {
+        return context;
+      }
+    }
+  }
+
+  let remainingCount = ids.length;
+  const foundContexts = new Array(remainingCount).fill(null);
+
+  for await (const context of iterable) {
+    // XXX Switch to const [index, id] of id.entries() when we move to Babel 7.
+    // See https://github.com/babel/babel/issues/5880.
+    for (let index = 0; index < ids.length; index++) {
+      const id = ids[index];
+      if (!foundContexts[index] && context.hasMessage(id)) {
+        foundContexts[index] = context;
+        remainingCount--;
+      }
+
+      // Return early when all ids have been mapped to contexts.
+      if (remainingCount === 0) {
+        return foundContexts;
+      }
+    }
+  }
+
+  return foundContexts;
+}

fluent/src/index.js

@@ -17,4 +17,4 @@ export {
 } from './types';
 
 export { default as CachedIterable } from './cached_iterable';
-export { mapContextSync } from './fallback';
+export { mapContextSync, mapContextAsync } from './fallback';