feat: add suggestion for no-return-await

lib/rules/no-return-await.js

@@ -13,6 +13,7 @@ const astUtils = require("./utils/ast-utils");
 /** @type {import('../shared/types').Rule} */
 module.exports = {
     meta: {
+        hasSuggestions: true,
         type: "suggestion",
 
         docs: {
@@ -29,6 +30,7 @@ module.exports = {
         ],
 
         messages: {
+            removeAwait: "Remove redundant `await`.",
             redundantUseOfAwait: "Redundant use of `await` on a return value."
         }
     },
@@ -44,7 +46,32 @@ module.exports = {
             context.report({
                 node: context.getSourceCode().getFirstToken(node),
                 loc: node.loc,
-                messageId: "redundantUseOfAwait"
+                messageId: "redundantUseOfAwait",
+                suggest: [
+                    {
+                        messageId: "removeAwait",
+                        fix(fixer) {
+                            const sourceCode = context.getSourceCode();
+                            const [awaitToken, tokenAfterAwait] = sourceCode.getTokens(node);
+
+                            const areAwaitAndAwaitedExpressionOnTheSameLine = awaitToken.loc.start.line === tokenAfterAwait.loc.start.line;
+
+                            if (!areAwaitAndAwaitedExpressionOnTheSameLine) {
+                                return null;
+                            }
+
+                            const [startOfAwait, endOfAwait] = awaitToken.range;
+
+                            const characterAfterAwait = sourceCode.text[endOfAwait];
+                            const trimLength = characterAfterAwait === " " ? 1 : 0;
+
+                            const range = [startOfAwait, endOfAwait + trimLength];
+
+                            return fixer.removeRange(range);
+                        }
+                    }
+                ]
+
             });
         }
 

tests/lib/rules/no-return-await.js

@@ -16,8 +16,24 @@ const { RuleTester } = require("../../../lib/rule-tester");
 // Tests
 //------------------------------------------------------------------------------
 
-// pending https://github.com/eslint/espree/issues/304, the type should be "Keyword"
-const errors = [{ messageId: "redundantUseOfAwait", type: "Identifier" }];
+/**
+ * Creates the list of errors that should be found by this rule
+ * @param {Object} options Options for creating errors
+ * @param {string} options.suggestionOutput The suggested output
+ * @returns {Array} the list of errors
+ */
+function createErrorList({ suggestionOutput: output } = {}) {
+
+    // pending https://github.com/eslint/espree/issues/304, the type should be "Keyword"
+    return [{
+        messageId: "redundantUseOfAwait",
+        type: "Identifier",
+        suggestions: output ? [{
+            messageId: "removeAwait", output
+        }] : []
+    }];
+}
+
 
 const ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 2017 } });
 
@@ -138,99 +154,103 @@ ruleTester.run("no-return-await", rule, {
     invalid: [
         {
             code: "\nasync function foo() {\n\treturn await bar();\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn bar();\n}\n" })
+        },
+        {
+            code: "\nasync function foo() {\n\treturn await(bar());\n}\n",
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (bar());\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (a, await bar());\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (a, bar());\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (a, b, await bar());\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (a, b, bar());\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (a && await bar());\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (a && bar());\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (a && b && await bar());\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (a && b && bar());\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (a || await bar());\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (a || bar());\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (a, b, (c, d, await bar()));\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (a, b, (c, d, bar()));\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (a, b, (c && await bar()));\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (a, b, (c && bar()));\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (await baz(), b, await bar());\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (await baz(), b, bar());\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (baz() ? await bar() : b);\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (baz() ? bar() : b);\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (baz() ? a : await bar());\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (baz() ? a : bar());\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (baz() ? (a, await bar()) : b);\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (baz() ? (a, bar()) : b);\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (baz() ? a : (b, await bar()));\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (baz() ? a : (b, bar()));\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (baz() ? (a && await bar()) : b);\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (baz() ? (a && bar()) : b);\n}\n" })
         },
         {
             code: "\nasync function foo() {\n\treturn (baz() ? a : (b && await bar()));\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\n\treturn (baz() ? a : (b && bar()));\n}\n" })
         },
         {
             code: "\nasync () => { return await bar(); }\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync () => { return bar(); }\n" })
         },
         {
             code: "\nasync () => await bar()\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync () => bar()\n" })
         },
         {
             code: "\nasync () => (a, b, await bar())\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync () => (a, b, bar())\n" })
         },
         {
             code: "\nasync () => (a && await bar())\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync () => (a && bar())\n" })
         },
         {
             code: "\nasync () => (baz() ? await bar() : b)\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync () => (baz() ? bar() : b)\n" })
         },
         {
             code: "\nasync () => (baz() ? a : (b, await bar()))\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync () => (baz() ? a : (b, bar()))\n" })
         },
         {
             code: "\nasync () => (baz() ? a : (b && await bar()))\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync () => (baz() ? a : (b && bar()))\n" })
         },
         {
             code: "\nasync function foo() {\nif (a) {\n\t\tif (b) {\n\t\t\treturn await bar();\n\t\t}\n\t}\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync function foo() {\nif (a) {\n\t\tif (b) {\n\t\t\treturn bar();\n\t\t}\n\t}\n}\n" })
         },
         {
             code: "\nasync () => {\nif (a) {\n\t\tif (b) {\n\t\t\treturn await bar();\n\t\t}\n\t}\n}\n",
-            errors
+            errors: createErrorList({ suggestionOutput: "\nasync () => {\nif (a) {\n\t\tif (b) {\n\t\t\treturn bar();\n\t\t}\n\t}\n}\n" })
         },
         {
             code: `
@@ -241,7 +261,16 @@ ruleTester.run("no-return-await", rule, {
                 }
               }
             `,
-            errors
+            errors: createErrorList({
+                suggestionOutput: `
+              async function foo() {
+                try {}
+                finally {
+                  return bar();
+                }
+              }
+            `
+            })
         },
         {
             code: `
@@ -252,7 +281,16 @@ ruleTester.run("no-return-await", rule, {
                 }
               }
             `,
-            errors
+            errors: createErrorList({
+                suggestionOutput: `
+              async function foo() {
+                try {}
+                catch (e) {
+                  return bar();
+                }
+              }
+            `
+            })
         },
         {
             code: `
@@ -262,15 +300,29 @@ ruleTester.run("no-return-await", rule, {
                 }
               } catch (e) {}
             `,
-            errors
+            errors: createErrorList({
+                suggestionOutput: `
+              try {
+                async function foo() {
+                  return bar();
+                }
+              } catch (e) {}
+            `
+            })
         },
         {
             code: `
               try {
                 async () => await bar();
               } catch (e) {}
             `,
-            errors
+            errors: createErrorList({
+                suggestionOutput: `
+              try {
+                async () => bar();
+              } catch (e) {}
+            `
+            })
         },
         {
             code: `
@@ -284,7 +336,64 @@ ruleTester.run("no-return-await", rule, {
                 }
               }
             `,
-            errors
+            errors: createErrorList({
+                suggestionOutput: `
+              async function foo() {
+                try {}
+                catch (e) {
+                  try {}
+                  catch (e) {
+                    return bar();
+                  }
+                }
+              }
+            `
+            })
+        },
+        {
+            code: `
+              async function foo() {
+                return await new Promise(resolve => {
+                  resolve(5);
+                });
+              }
+            `,
+            errors: createErrorList({
+                suggestionOutput: `
+              async function foo() {
+                return new Promise(resolve => {
+                  resolve(5);
+                });
+              }
+            `
+            })
+        },
+        {
+            code: `
+              async () => {
+                return await (
+                  foo()
+                )
+              };
+            `,
+            errors: createErrorList({
+                suggestionOutput: `
+              async () => {
+                return (
+                  foo()
+                )
+              };
+            `
+            })
+        },
+        {
+            code: `
+              async function foo() {
+                return await // Test
+                  5;
+              }
+            `,
+            errors: createErrorList()
         }
     ]
 });