fix(valid-expect-in-promise): support await in arrays (#949)

Author: G-Rath

src/rules/__tests__/valid-expect-in-promise.test.ts

@@ -120,6 +120,28 @@ ruleTester.run('valid-expect-in-promise', rule, {
           return number + 1;
         });
 
+        expect([await promise]).toHaveLength(1);
+      });
+    `,
+    dedent`
+      it('is valid', async () => {
+        const promise = loadNumber().then(number => {
+          expect(typeof number).toBe('number');
+
+          return number + 1;
+        });
+
+        expect([[await promise]]).toHaveLength(1);
+      });
+    `,
+    dedent`
+      it('is valid', async () => {
+        const promise = loadNumber().then(number => {
+          expect(typeof number).toBe('number');
+
+          return number + 1;
+        });
+
         logValue(await promise);
       });
     `,

src/rules/valid-expect-in-promise.ts

@@ -143,6 +143,35 @@ const isPromiseMethodThatUsesValue = (
   return isIdentifier(node.argument, name);
 };
 
+/**
+ * Attempts to determine if the runtime value represented by the given `identifier`
+ * is `await`ed within the given array of elements
+ */
+const isValueAwaitedInElements = (
+  name: string,
+  elements:
+    | TSESTree.ArrayExpression['elements']
+    | TSESTree.CallExpression['arguments'],
+): boolean => {
+  for (const element of elements) {
+    if (
+      element.type === AST_NODE_TYPES.AwaitExpression &&
+      isIdentifier(element.argument, name)
+    ) {
+      return true;
+    }
+
+    if (
+      element.type === AST_NODE_TYPES.ArrayExpression &&
+      isValueAwaitedInElements(name, element.elements)
+    ) {
+      return true;
+    }
+  }
+
+  return false;
+};
+
 /**
  * Attempts to determine if the runtime value represented by the given `identifier`
  * is `await`ed as an argument along the given call expression
@@ -155,13 +184,8 @@ const isValueAwaitedInArguments = (
 
   while (node) {
     if (node.type === AST_NODE_TYPES.CallExpression) {
-      for (const argument of node.arguments) {
-        if (
-          argument.type === AST_NODE_TYPES.AwaitExpression &&
-          isIdentifier(argument.argument, name)
-        ) {
-          return true;
-        }
+      if (isValueAwaitedInElements(name, node.arguments)) {
+        return true;
       }
 
       node = node.callee;