chore: use explicit matcher call context

Author: pavelfeldman

packages/playwright/src/matchers/expect.ts

@@ -110,13 +110,13 @@ function createMatchers(actual: unknown, info: ExpectMetaInfo, prefix: string[])
   return new Proxy(expectLibrary(actual), new ExpectMetaInfoProxyHandler(info, prefix));
 }
 
-const getCustomMatchersSymbol = Symbol('get custom matchers');
+const userMatchersSymbol = Symbol('userMatchers');
 
 function qualifiedMatcherName(qualifier: string[], matcherName: string) {
   return qualifier.join(':') + '$' + matcherName;
 }
 
-function createExpect(info: ExpectMetaInfo, prefix: string[], customMatchers: Record<string, Function>) {
+function createExpect(info: ExpectMetaInfo, prefix: string[], userMatchers: Record<string, Function>) {
   const expectInstance: Expect<{}> = new Proxy(expectLibrary, {
     apply: function(target: any, thisArg: any, argumentsList: [unknown, ExpectMessage?]) {
       const [actual, messageOrOptions] = argumentsList;
@@ -130,7 +130,7 @@ function createExpect(info: ExpectMetaInfo, prefix: string[], customMatchers: Re
       return createMatchers(actual, newInfo, prefix);
     },
 
-    get: function(target: any, property: string | typeof getCustomMatchersSymbol) {
+    get: function(target: any, property: string | typeof userMatchersSymbol) {
       if (property === 'configure')
         return configure;
 
@@ -139,27 +139,14 @@ function createExpect(info: ExpectMetaInfo, prefix: string[], customMatchers: Re
           const qualifier = [...prefix, createGuid()];
 
           const wrappedMatchers: any = {};
-          const extendedMatchers: any = { ...customMatchers };
           for (const [name, matcher] of Object.entries(matchers)) {
-            wrappedMatchers[name] = function(...args: any[]) {
-              const { isNot, promise, utils } = this;
-              const newThis: ExpectMatcherState = {
-                isNot,
-                promise,
-                utils,
-                timeout: currentExpectTimeout()
-              };
-              (newThis as any).equals = throwUnsupportedExpectMatcherError;
-              return (matcher as any).call(newThis, ...args);
-            };
+            wrappedMatchers[name] = wrapPlaywrightMatcherToPassNiceThis(matcher);
             const key = qualifiedMatcherName(qualifier, name);
             wrappedMatchers[key] = wrappedMatchers[name];
             Object.defineProperty(wrappedMatchers[key], 'name', { value: name });
-            extendedMatchers[name] = wrappedMatchers[key];
           }
           expectLibrary.extend(wrappedMatchers);
-
-          return createExpect(info, qualifier, extendedMatchers);
+          return createExpect(info, qualifier, { ...userMatchers, ...matchers });
         };
       }
 
@@ -169,8 +156,8 @@ function createExpect(info: ExpectMetaInfo, prefix: string[], customMatchers: Re
         };
       }
 
-      if (property === getCustomMatchersSymbol)
-        return customMatchers;
+      if (property === userMatchersSymbol)
+        return userMatchers;
 
       if (property === 'poll') {
         return (actual: unknown, messageOrOptions?: ExpectMessage & { timeout?: number, intervals?: number[] }) => {
@@ -197,12 +184,56 @@ function createExpect(info: ExpectMetaInfo, prefix: string[], customMatchers: Re
         newInfo.poll!.intervals = configuration._poll.intervals ?? newInfo.poll!.intervals;
       }
     }
-    return createExpect(newInfo, prefix, customMatchers);
+    return createExpect(newInfo, prefix, userMatchers);
   };
 
   return expectInstance;
 }
 
+// Expect wraps matchers, so there is no way to pass this information to the raw Playwright matcher.
+// Rely on sync call sequence to seed each matcher call with the context.
+type MatcherCallContext = {
+  expectInfo: ExpectMetaInfo;
+  testInfo: TestInfoImpl | null;
+};
+
+let matcherCallContext: MatcherCallContext | undefined;
+
+function setMatcherCallContext(context: MatcherCallContext) {
+  matcherCallContext = context;
+}
+
+function takeMatcherCallContext(): MatcherCallContext {
+  try {
+    return matcherCallContext!;
+  } finally {
+    matcherCallContext = undefined;
+  }
+}
+
+type ExpectMatcherStateInternal = ExpectMatcherState & {
+  _context: MatcherCallContext | undefined;
+};
+
+const defaultExpectTimeout = 5000;
+
+function wrapPlaywrightMatcherToPassNiceThis(matcher: any) {
+  return function(this: any, ...args: any[]) {
+    const { isNot, promise, utils } = this;
+    const context = takeMatcherCallContext();
+    const timeout = context.expectInfo.timeout ?? context.testInfo?._projectInternal?.expect?.timeout ?? defaultExpectTimeout;
+    const newThis: ExpectMatcherStateInternal = {
+      isNot,
+      promise,
+      utils,
+      timeout,
+      _context: context,
+    };
+    (newThis as any).equals = throwUnsupportedExpectMatcherError;
+    return matcher.call(newThis, ...args);
+  };
+}
+
 function throwUnsupportedExpectMatcherError() {
   throw new Error('It looks like you are using custom expect matchers that are not compatible with Playwright. See https://aka.ms/playwright/expect-compatibility');
 }
@@ -299,8 +330,7 @@ class ExpectMetaInfoProxyHandler implements ProxyHandler<any> {
     }
     return (...args: any[]) => {
       const testInfo = currentTestInfo();
-      // We assume that the matcher will read the current expect timeout the first thing.
-      setCurrentExpectConfigureTimeout(this._info.timeout);
+      setMatcherCallContext({ expectInfo: this._info, testInfo });
       if (!testInfo)
         return matcher.call(target, ...args);
 
@@ -362,7 +392,7 @@ class ExpectMetaInfoProxyHandler implements ProxyHandler<any> {
 async function pollMatcher(qualifiedMatcherName: string, info: ExpectMetaInfo, prefix: string[], ...args: any[]) {
   const testInfo = currentTestInfo();
   const poll = info.poll!;
-  const timeout = poll.timeout ?? currentExpectTimeout();
+  const timeout = poll.timeout ?? info.timeout ?? testInfo?._projectInternal?.expect?.timeout ?? defaultExpectTimeout;
   const { deadline, timeoutMessage } = testInfo ? testInfo._deadlineForMatcher(timeout) : TestInfoImpl._defaultDeadlineForMatcher(timeout);
 
   const result = await pollAgainstDeadline<Error|undefined>(async () => {
@@ -398,22 +428,6 @@ async function pollMatcher(qualifiedMatcherName: string, info: ExpectMetaInfo, p
   }
 }
 
-let currentExpectConfigureTimeout: number | undefined;
-
-function setCurrentExpectConfigureTimeout(timeout: number | undefined) {
-  currentExpectConfigureTimeout = timeout;
-}
-
-function currentExpectTimeout() {
-  if (currentExpectConfigureTimeout !== undefined)
-    return currentExpectConfigureTimeout;
-  const testInfo = currentTestInfo();
-  let defaultExpectTimeout = testInfo?._projectInternal?.expect?.timeout;
-  if (typeof defaultExpectTimeout === 'undefined')
-    defaultExpectTimeout = 5000;
-  return defaultExpectTimeout;
-}
-
 function computeArgsSuffix(matcherName: string, args: any[]) {
   let value = '';
   if (matcherName === 'toHaveScreenshot')
@@ -426,7 +440,7 @@ export const expect: Expect<{}> = createExpect({}, [], {}).extend(customMatchers
 export function mergeExpects(...expects: any[]) {
   let merged = expect;
   for (const e of expects) {
-    const internals = e[getCustomMatchersSymbol];
+    const internals = e[userMatchersSymbol];
     if (!internals) // non-playwright expects mutate the global expect, so we don't need to do anything special
       continue;
     merged = merged.extend(internals);