fix: simplify zone patch test method impl (#361)

To cover all jest test methods, the `wrapTestInZone` method is simplified
to just run the `testBody` in the `testProxyZone` without differentiating between
the arguments of `each` (to consider `done`) and `testBody` lengths.

example/src/app/app.component.spec.ts

@@ -108,6 +108,34 @@ describe('AppComponent', () => {
     expect(arg2).toBe(2);
     done();
   });
+
+  it.each`
+    foo  | bar
+    ${1} | ${2}
+  `('it.each should work with table as a tagged template literal', ({ foo, bar }) => {
+    expect(foo).toBe(1);
+    expect(bar).toBe(2);
+  });
+
+  (it.each`
+    foo  | bar
+    ${1} | ${2}
+  ` as any)(
+    'it.each should work with table as a tagged template literal with done',
+    ({ foo, bar }, done) => {
+      expect(foo).toBe(1);
+      expect(bar).toBe(2);
+      done();
+    }
+  );
+
+  it.each`
+    foo  | bar
+    ${1} | ${2}
+  `('(async) it.each should work with table as a tagged template literal', async ({ foo, bar }) => {
+    expect(foo).toBe(1);
+    expect(bar).toBe(2);
+  });
 });
 
 test.todo('a sample todo');

src/zone-patch/index.js

@@ -44,51 +44,27 @@ function wrapDescribeInZone(describeBody) {
 // Create a proxy zone in which to run `test` blocks so that the tests function
 // can retroactively install different zones.
 const testProxyZone = ambientZone.fork(new ProxyZoneSpec());
-function wrapTestInZone(testBody, eachArgs) {
+function wrapTestInZone(testBody) {
   if (testBody === undefined) {
     return;
   }
 
-  if (!eachArgs || eachArgs.length === 0 || eachArgs[0].length === 0) {
-    // If we are not handling `test.each`, then the parameter of `testBody`
-    // will be 0 or 1, if it is 1, then we need to return a function with
-    // done parameter
+  const wrappedFunc = function() {
+    return testProxyZone.run(testBody, null, arguments);
+  };
+  try {
+    Object.defineProperty(wrappedFunc, 'length', {
+      configurable: true,
+      writable: true,
+      enumerable: false
+    });
+    wrappedFunc.length = testBody.length;
+  } catch (e) {
     return testBody.length === 0
       ? () => testProxyZone.run(testBody, null)
       : done => testProxyZone.run(testBody, null, [done]);
-  } else {
-    // Dynamically create a Function to contain the same length
-    // of the parameters as the testBody
-    // For example:
-    // ```
-    // test.each([[1, 2]])('test.each', (arg1, arg2) => {});
-    // ```
-    // In this case we need to return a function like this
-    // ```
-    // return function(arg1, arg2) {
-    //   return testProxyZone.run(testBody, null, [arg1, arg2]);
-    // }
-    // ```
-    const len = eachArgs[0].length;
-    const args = [];
-    let argString = '';
-    for (let i = 0; i < len; i++) {
-      args.push('arg' + i);
-      argString += 'arg' + i;
-      if (i !== len - 1) {
-        argString += ', ';
-      }
-    }
-    args.push('testBody');
-    args.push('testProxyZone');
-    if (len < testBody.length) {
-      args.push('done');
-      argString += ', done';
-    }
-    const funcBody = `
-      return testProxyZone.run(testBody, null, [${argString}])`;
-    return new Function(args, funcBody);
   }
+  return wrappedFunc;
 }
 
 /**
@@ -108,29 +84,7 @@ const bindDescribe = originalJestFn =>
 const bindTest = originalJestFn =>
   function(...eachArgs) {
     return function(...args) {
-      const testBody = args[1];
-      if (
-        testBody.length > 0 &&
-        Array.isArray(eachArgs) &&
-        eachArgs.length > 0 &&
-        eachArgs[0].length > 0
-      ) {
-        // check whether eachArgs is a 1D array
-        if (!Array.isArray(eachArgs[0][0])) {
-          // transfer eachArgs from 1D to 2D array
-          eachArgs = eachArgs.map(row => row.map(a => [a]));
-        }
-      }
-      args[1] = wrapTestInZone(args[1], ...eachArgs);
-      if (testBody.length > 0 || (eachArgs.length > 0 && eachArgs[0].length > 0)) {
-        eachArgs.forEach(row => {
-          const modifiedRow = row.map(a => {
-            a.push(testBody);
-            a.push(testProxyZone);
-          });
-          return modifiedRow;
-        });
-      }
+      args[1] = wrapTestInZone(args[1]);
       return originalJestFn.apply(this, eachArgs).apply(this, args);
     };
   };