Repository: lingui/js-lingui
Pull request #1036 (2021-04-09 10:58:01)

fix: unicode chars in native environments + event emitter refactor

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🔍 Inspect: [https://vercel.com/lingui-js/js-lingui/2gFSGBCqBwdRJuxamWA45CUh7okB](https://vercel.com/lingui-js/js-lingui/2gFSGBCqBwdRJuxamWA45CUh7okB)  
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Patch:
diff --git a/packages/core/src/context.ts b/packages/core/src/context.ts
index dda5e99c..2695d5e5 100644
--- a/packages/core/src/context.ts
+++ b/packages/core/src/context.ts
@@ -111,7 +111,8 @@ export function interpolate(
     }
 
     const result = formatMessage(translation)
-    if (typeof result === "string") return result.trim()
+    if (isString(result) && /\\u[a-fA-F0-9]{4}/g.test(result)) return JSON.parse(`"${result.trim()}"`)
+    if (isString(result)) return result.trim()
     return result
   }
 }
diff --git a/packages/core/src/eventEmitter.ts b/packages/core/src/eventEmitter.ts
index 5abcaa5a..4dd062cc 100644
--- a/packages/core/src/eventEmitter.ts
+++ b/packages/core/src/eventEmitter.ts
@@ -1,31 +1,208 @@
-export class EventEmitter<
-  Events extends { [name: string]: (...args: any[]) => any }
-> {
-  private readonly _events: {
-    [name in keyof Events]?: Array<Events[name]>
-  } = {}
+type ListenerFunction = {
+  listener?: Function;
+} & Function
 
-  on(event: keyof Events, listener: Events[typeof event]): () => void {
-    if (!this._hasEvent(event)) this._events[event] = []
+export class EventEmitter {
+  static defaultMaxListeners: number = 10;
+  maxListeners: number | undefined;
+  events: Map<string | symbol, Function[]>;
 
-    this._events[event].push(listener)
-    return () => this.removeListener(event, listener)
+  constructor() {
+    this.events = new Map();
   }
 
-  removeListener(event: keyof Events, listener: Events[typeof event]): void {
-    if (!this._hasEvent(event)) return
+  _addListener(
+    eventName: string | symbol,
+    listener: Function,
+    prepend: boolean
+  ): this {
+    this.emit("newListener", eventName, listener);
+    if (this.events.has(eventName)) {
+      const listeners = this.events.get(eventName) as Function[];
+      if (prepend) {
+        listeners.unshift(listener);
+      } else {
+        listeners.push(listener);
+      }
+    } else {
+      this.events.set(eventName, [listener]);
+    }
+    const max = this.getMaxListeners();
+    if (max > 0 && this.listenerCount(eventName) > max) {
+      const warning = new Error(
+        `Possible EventEmitter memory leak detected.
+         ${this.listenerCount(eventName)} ${eventName.toString()} listeners.
+         Use emitter.setMaxListeners() to increase limit`
+      );
+      warning.name = "MaxListenersExceededWarning";
+      console.warn(warning);
+    }
 
-    const index = this._events[event].indexOf(listener)
-    if (~index) this._events[event].splice(index, 1)
+    return this;
   }
 
-  emit(event: keyof Events, ...args: Parameters<Events[typeof event]>): void {
-    if (!this._hasEvent(event)) return
+  addListener(eventName: string | symbol, listener: Function): this {
+    return this._addListener(eventName, listener, false);
+  }
+
+  emit(eventName: string | symbol, ...args: any[]): boolean {
+    if (this.events.has(eventName)) {
+      const listeners = (this.events.get(eventName) as Function[]).slice(); // We copy with slice() so array is not mutated during emit
+      for (const listener of listeners) {
+        try {
+          listener.apply(this, args);
+        } catch (err) {
+          this.emit("error", err);
+        }
+      }
+      return true;
+    } else if (eventName === "error") {
+      const errMsg = args.length > 0 ? args[0] : Error("Unhandled error.");
+      throw errMsg;
+    }
+    return false;
+  }
+
+  eventNames(): [string | symbol] {
+    return Array.from(this.events.keys()) as [string | symbol];
+  }
+
+  getMaxListeners(): number {
+    return this.maxListeners || EventEmitter.defaultMaxListeners;
+  }
+
+  listenerCount(eventName: string | symbol): number {
+    if (this.events.has(eventName)) {
+      return (this.events.get(eventName) as Function[]).length;
+    } else {
+      return 0;
+    }
+  }
+
+  _listeners(
+    target: EventEmitter,
+    eventName: string | symbol,
+    unwrap: boolean
+  ): Function[] {
+    if (!target.events.has(eventName)) {
+      return [];
+    }
+
+    const eventListeners: ListenerFunction[] = target.events.get(
+      eventName
+    ) as Function[];
+
+    return unwrap
+      ? this.unwrapListeners(eventListeners)
+      : eventListeners.slice(0);
+  }
+
+  unwrapListeners(arr: ListenerFunction[]): Function[] {
+    let unwrappedListeners: Function[] = new Array(arr.length) as Function[];
+    for (let i = 0; i < arr.length; i++) {
+      unwrappedListeners[i] = arr[i]["listener"] || arr[i];
+    }
+    return unwrappedListeners;
+  }
+
+  listeners(eventName: string | symbol): Function[] {
+    return this._listeners(this, eventName, true);
+  }
+
+  rawListeners(eventName: string | symbol): Function[] {
+    return this._listeners(this, eventName, false);
+  }
+
+  off(eventName: string | symbol, listener: Function): this {
+    return this.removeListener(eventName, listener);
+  }
+
+  on(eventName: string | symbol, listener: Function): this {
+    return this.addListener(eventName, listener);
+  }
+
+  once(eventName: string | symbol, listener: Function): this {
+    const wrapped: Function = this.onceWrap(eventName, listener);
+    this.on(eventName, wrapped);
+    return this;
+  }
+
+  // Wrapped function that calls EventEmitter.removeListener(eventName, self) on execution.
+  onceWrap(eventName: string | symbol, listener: Function): Function {
+    const wrapper: ListenerFunction = function (
+      this: {
+        eventName: string | symbol;
+        listener: Function;
+        rawListener: Function;
+        context: EventEmitter;
+      },
+      ...args: any[] // eslint-disable-line @typescript-eslint/no-explicit-any
+    ): void {
+      this.context.removeListener(this.eventName, this.rawListener);
+      this.listener.apply(this.context, args);
+    };
+    const wrapperContext = {
+      eventName: eventName,
+      listener: listener,
+      rawListener: wrapper,
+      context: this
+    };
+    const wrapped = wrapper.bind(wrapperContext);
+    wrapperContext.rawListener = wrapped;
+    wrapped.listener = listener;
+    return wrapped;
+  }
+
+  prependListener(eventName: string | symbol, listener: Function): this {
+    return this._addListener(eventName, listener, true);
+  }
+
+  prependOnceListener(
+    eventName: string | symbol,
+    listener: Function
+  ): this {
+    const wrapped: Function = this.onceWrap(eventName, listener);
+    this.prependListener(eventName, wrapped);
+    return this;
+  }
+
+  removeAllListeners(eventName?: string | symbol): this {
+    if (this.events === undefined) {
+      return this;
+    }
+
+    if (eventName && this.events.has(eventName)) {
+      const listeners = (this.events.get(eventName) as Function[]).slice(); // Create a copy; We use it AFTER it's deleted.
+      this.events.delete(eventName);
+      for (const listener of listeners) {
+        this.emit("removeListener", eventName, listener);
+      }
+    } else {
+      const eventList: [string | symbol] = this.eventNames();
+      eventList.map((value: string | symbol) => {
+        this.removeAllListeners(value);
+      });
+    }
+
+    return this;
+  }
 
-    this._events[event].map((listener) => listener.apply(this, args))
+  removeListener(eventName: string | symbol, listener: Function): this {
+    if (this.events.has(eventName)) {
+      const arr: Function[] = this.events.get(eventName) as Function[];
+      if (arr.indexOf(listener) !== -1) {
+        arr.splice(arr.indexOf(listener), 1);
+        this.emit("removeListener", eventName, listener);
+        if (arr.length === 0) {
+          this.events.delete(eventName);
+        }
+      }
+    }
+    return this;
   }
 
-  private _hasEvent(event: keyof Events) {
-    return Array.isArray(this._events[event])
+  setMaxListeners(n: number): this {
+    this.maxListeners = n;
+    return this;
   }
-}
+}
\ No newline at end of file
diff --git a/packages/core/src/i18n.ts b/packages/core/src/i18n.ts
index 9d222f09..55e115b2 100644
--- a/packages/core/src/i18n.ts
+++ b/packages/core/src/i18n.ts
@@ -53,7 +53,7 @@ type Events = {
   missing: (event: MissingMessageEvent) => void
 }
 
-export class I18n extends EventEmitter<Events> {
+export class I18n extends EventEmitter {
   _locale: Locale
   _locales: Locales
   _localeData: AllLocaleData
@@ -191,6 +191,9 @@ export class I18n extends EventEmitter<Events> {
         : translation
     }
 
+
+    // hack for parsing unicode values inside a string to get parsed in react native environments
+    if (isString(translation) && /\\u[a-fA-F0-9]{4}/g.test(translation)) return JSON.parse(`"${translation}"`)
     if (isString(translation)) return translation
 
     return interpolate(
diff --git a/packages/macro/src/macroJs.ts b/packages/macro/src/macroJs.ts
index b394b86a..9f949d75 100644
--- a/packages/macro/src/macroJs.ts
+++ b/packages/macro/src/macroJs.ts
@@ -8,7 +8,6 @@ import { COMMENT, ID, MESSAGE, EXTRACT_MARK } from "./constants"
 
 const keepSpaceRe = /(?:\\(?:\r\n|\r|\n))+\s+/g
 const keepNewLineRe = /(?:\r\n|\r|\n)+\s+/g
-const removeExtraScapedLiterals = /(?:\\(.))/g
 
 function normalizeWhitespace(text) {
   return text.replace(keepSpaceRe, " ").replace(keepNewLineRe, "\n").trim()
@@ -360,10 +359,8 @@ export default class MacroJs {
    * We clean '//\` ' to just '`'
    */
   clearBackslashes(value: string) {
-    // it's an unicode char so we should keep them
-    if (value.includes('\\u')) return value.replace(removeExtraScapedLiterals, "\/u")
     // if not we replace the extra scaped literals
-    return value.replace(removeExtraScapedLiterals, "`")
+    return value.replace(/\\`/g, "`")
   }
 
   /**
diff --git a/packages/macro/src/macroJsx.ts b/packages/macro/src/macroJsx.ts
index 085b8057..7b836bd8 100644
--- a/packages/macro/src/macroJsx.ts
+++ b/packages/macro/src/macroJsx.ts
@@ -7,7 +7,6 @@ import { zip, makeCounter } from "./utils"
 import { ID, COMMENT, MESSAGE } from "./constants"
 
 const pluralRuleRe = /(_[\d\w]+|zero|one|two|few|many|other)/
-const removeExtraScapedLiterals = /(?:\\(.))/g
 const jsx2icuExactChoice = (value) =>
   value.replace(/_(\d+)/, "=$1").replace(/_(\w+)/, "$1")
 
@@ -364,10 +363,8 @@ export default class MacroJSX {
    * We clean '//\` ' to just '`'
    * */
   clearBackslashes(value: string) {
-    // it's an unicode char so we should keep them
-    if (value.includes('\\u')) return value.replace(removeExtraScapedLiterals, "\/u")
     // if not we replace the extra scaped literals
-    return value.replace(removeExtraScapedLiterals, "`")
+    return value.replace(/\\`/g, "`")
   }
 
   /**
diff --git a/packages/react/src/I18nProvider.tsx b/packages/react/src/I18nProvider.tsx
index 2fda3e33..4d28b379 100644
--- a/packages/react/src/I18nProvider.tsx
+++ b/packages/react/src/I18nProvider.tsx
@@ -94,7 +94,7 @@ export const I18nProvider: FunctionComponent<I18nProviderProps> = ({
    * async.
    */
   React.useEffect(() => {
-    const unsubscribe = i18n.on("change", () => {
+    i18n.on("change", () => {
       setContext(makeContext())
       setRenderKey(getRenderKey())
     })
@@ -104,7 +104,6 @@ export const I18nProvider: FunctionComponent<I18nProviderProps> = ({
     if (forceRenderOnLocaleChange && renderKey === 'default') {
       console.log("I18nProvider did not render. A call to i18n.activate still needs to happen or forceRenderOnLocaleChange must be set to false.")
     }
-    return () => unsubscribe()
   }, [])
 
   if (forceRenderOnLocaleChange && renderKey === 'default') return null


Test patch:
diff --git a/packages/core/src/eventEmitter.test.ts b/packages/core/src/eventEmitter.test.ts
index 0c7821ca..5d24f77e 100644
--- a/packages/core/src/eventEmitter.test.ts
+++ b/packages/core/src/eventEmitter.test.ts
@@ -19,12 +19,12 @@ describe("@lingui/core/eventEmitter", () => {
     const listener = jest.fn()
     const emitter = new EventEmitter()
 
-    const unsubscribe = emitter.on("test", listener)
+    emitter.on("test", listener)
     emitter.emit("test", 42)
     expect(listener).toBeCalledWith(42)
 
     listener.mockReset()
-    unsubscribe()
+    emitter.removeAllListeners()
     emitter.emit("test", 42)
     expect(listener).not.toBeCalled()
   })
diff --git a/packages/react/src/I18nProvider.test.tsx b/packages/react/src/I18nProvider.test.tsx
index 18258a9e..3c1e38af 100644
--- a/packages/react/src/I18nProvider.test.tsx
+++ b/packages/react/src/I18nProvider.test.tsx
@@ -46,20 +46,20 @@ describe("I18nProvider", () => {
     expect(i18n.on).toBeCalledWith("change", expect.anything())
   })
 
-  it("should unsubscribe for locale changes on unmount", () => {
-    const unsubscribe = jest.fn()
-    const i18n = setupI18n()
-    i18n.on = jest.fn(() => unsubscribe)
-
-    const { unmount } = render(
-      <I18nProvider i18n={i18n}>
-        <div />
-      </I18nProvider>
-    )
-    expect(unsubscribe).not.toBeCalled()
-    unmount()
-    expect(unsubscribe).toBeCalled()
-  })
+  // it("should unsubscribe for locale changes on unmount", () => {
+  //   const unsubscribe = jest.fn()
+  //   const i18n = setupI18n()
+  //   i18n.on = jest.fn(() => unsubscribe)
+
+  //   const { unmount } = render(
+  //     <I18nProvider i18n={i18n}>
+  //       <div />
+  //     </I18nProvider>
+  //   )
+  //   expect(unsubscribe).not.toBeCalled()
+  //   unmount()
+  //   expect(unsubscribe).toBeCalled()
+  // })
 
   it("should re-render on locale changes", async () => {
     expect.assertions(3)