Hoist state to file level (#96)

This fixes issues without writing the extracted messages out to the
filesystem when multiple instances of the plugin are being applied.

This also removes the CLI usage docs which say to use `--plugins`
option because this is not useful for this plugin since it needs to
be configured via `.babelrc` or use via Babel's API.

Fixes #92

Author: ericf

README.md

@@ -42,12 +42,6 @@ If a message descriptor has a `description`, it'll be removed from the source af
 
 - **`moduleSourceName`**: The ES6 module source name of the React Intl package. Defaults to: `"react-intl"`, but can be changed to another name/path to React Intl.
 
-### Via CLI
-
-```sh
-$ babel --plugins react-intl script.js
-```
-
 ### Via Node API
 
 The extract message descriptors are available via the `metadata` property on the object returned from Babel's `transform()` API:

src/index.js

@@ -20,15 +20,16 @@ const FUNCTION_NAMES = [
 
 const DESCRIPTOR_PROPS = new Set(['id', 'description', 'defaultMessage']);
 
-const EXTRACTED_TAG = Symbol('ReactIntlExtracted');
+const EXTRACTED = Symbol('ReactIntlExtracted');
+const MESSAGES  = Symbol('ReactIntlMessages');
 
 export default function ({types: t}) {
     function getModuleSourceName(opts) {
         return opts.moduleSourceName || 'react-intl';
     }
 
     function evaluatePath(path) {
-        let evaluated = path.evaluate();
+        const evaluated = path.evaluate();
         if (evaluated.confident) {
             return evaluated.value;
         }
@@ -62,7 +63,7 @@ export default function ({types: t}) {
     }
 
     function getICUMessageValue(messagePath, {isJSXSource = false} = {}) {
-        let message = getMessageDescriptorValue(messagePath);
+        const message = getMessageDescriptorValue(messagePath);
 
         try {
             return printICUMessage(message);
@@ -90,7 +91,7 @@ export default function ({types: t}) {
 
     function createMessageDescriptor(propPaths) {
         return propPaths.reduce((hash, [keyPath, valuePath]) => {
-            let key = getMessageDescriptorKey(keyPath);
+            const key = getMessageDescriptorKey(keyPath);
 
             if (DESCRIPTOR_PROPS.has(key)) {
                 hash[key] = valuePath;
@@ -102,7 +103,7 @@ export default function ({types: t}) {
 
     function evaluateMessageDescriptor({...descriptor}, {isJSXSource = false} = {}) {
         Object.keys(descriptor).forEach((key) => {
-            let valuePath = descriptor[key];
+            const valuePath = descriptor[key];
 
             if (key === 'defaultMessage') {
                 descriptor[key] = getICUMessageValue(valuePath, {isJSXSource});
@@ -115,16 +116,17 @@ export default function ({types: t}) {
     }
 
     function storeMessage({id, description, defaultMessage}, path, state) {
-        const {file, opts, reactIntl} = state;
+        const {file, opts} = state;
 
         if (!(id && defaultMessage)) {
             throw path.buildCodeFrameError(
                 '[React Intl] Message Descriptors require an `id` and `defaultMessage`.'
             );
         }
 
-        if (reactIntl.messages.has(id)) {
-            let existing = reactIntl.messages.get(id);
+        const messages = file.get(MESSAGES);
+        if (messages.has(id)) {
+            const existing = messages.get(id);
 
             if (description !== existing.description ||
                 defaultMessage !== existing.defaultMessage) {
@@ -155,7 +157,7 @@ export default function ({types: t}) {
             };
         }
 
-        reactIntl.messages.set(id, {id, description, defaultMessage, ...loc});
+        messages.set(id, {id, description, defaultMessage, ...loc});
     }
 
     function referencesImport(path, mod, importedNames) {
@@ -167,51 +169,50 @@ export default function ({types: t}) {
     }
 
     function tagAsExtracted(path) {
-        path.node[EXTRACTED_TAG] = true;
+        path.node[EXTRACTED] = true;
     }
 
     function wasExtracted(path) {
-        return !!path.node[EXTRACTED_TAG];
+        return !!path.node[EXTRACTED];
     }
 
     return {
-        visitor: {
-            Program: {
-                enter(path, state) {
-                    state.reactIntl = {
-                        messages: new Map(),
-                    };
-                },
-
-                exit(path, state) {
-                    const {file, opts, reactIntl} = state;
-                    const {basename, filename}    = file.opts;
-
-                    let descriptors = [...reactIntl.messages.values()];
-                    file.metadata['react-intl'] = {messages: descriptors};
-
-                    if (opts.messagesDir && descriptors.length > 0) {
-                        // Make sure the relative path is "absolute" before
-                        // joining it with the `messagesDir`.
-                        let relativePath = p.join(
-                            p.sep,
-                            p.relative(process.cwd(), filename)
-                        );
+        pre(file) {
+            if (!file.has(MESSAGES)) {
+                file.set(MESSAGES, new Map());
+            }
+        },
 
-                        let messagesFilename = p.join(
-                            opts.messagesDir,
-                            p.dirname(relativePath),
-                            basename + '.json'
-                        );
+        post(file) {
+            const {opts} = this;
+            const {basename, filename} = file.opts;
 
-                        let messagesFile = JSON.stringify(descriptors, null, 2);
+            const messages = file.get(MESSAGES);
+            const descriptors = [...messages.values()];
+            file.metadata['react-intl'] = {messages: descriptors};
 
-                        mkdirpSync(p.dirname(messagesFilename));
-                        writeFileSync(messagesFilename, messagesFile);
-                    }
-                },
-            },
+            if (opts.messagesDir && descriptors.length > 0) {
+                // Make sure the relative path is "absolute" before
+                // joining it with the `messagesDir`.
+                const relativePath = p.join(
+                    p.sep,
+                    p.relative(process.cwd(), filename)
+                );
 
+                const messagesFilename = p.join(
+                    opts.messagesDir,
+                    p.dirname(relativePath),
+                    basename + '.json'
+                );
+
+                const messagesFile = JSON.stringify(descriptors, null, 2);
+
+                mkdirpSync(p.dirname(messagesFilename));
+                writeFileSync(messagesFilename, messagesFile);
+            }
+        },
+
+        visitor: {
             JSXOpeningElement(path, state) {
                 if (wasExtracted(path)) {
                     return;
@@ -232,7 +233,7 @@ export default function ({types: t}) {
                 }
 
                 if (referencesImport(name, moduleSourceName, COMPONENT_NAMES)) {
-                    let attributes = path.get('attributes')
+                    const attributes = path.get('attributes')
                         .filter((attr) => attr.isJSXAttribute());
 
                     let descriptor = createMessageDescriptor(
@@ -260,7 +261,7 @@ export default function ({types: t}) {
 
                         // Remove description since it's not used at runtime.
                         attributes.some((attr) => {
-                            let ketPath = attr.get('name');
+                            const ketPath = attr.get('name');
                             if (getMessageDescriptorKey(ketPath) === 'description') {
                                 attr.remove();
                                 return true;
@@ -295,7 +296,7 @@ export default function ({types: t}) {
                         return;
                     }
 
-                    let properties = messageObj.get('properties');
+                    const properties = messageObj.get('properties');
 
                     let descriptor = createMessageDescriptor(
                         properties.map((prop) => [
@@ -325,7 +326,7 @@ export default function ({types: t}) {
                 }
 
                 if (referencesImport(callee, moduleSourceName, FUNCTION_NAMES)) {
-                    let messagesObj = path.get('arguments')[0];
+                    const messagesObj = path.get('arguments')[0];
 
                     assertObjectExpression(messagesObj);