feat(typescript-estree): align optional fields (#1429)

Author: armano2

packages/parser/tests/lib/__snapshots__/typescript.ts.snap

@@ -0,0 +1,17 @@
+const computed1 = "buzz";
+const computed2 = "bazz";
+const obj = {
+  member: "member",
+  member2: "member2",
+};
+class X {
+  [computed1]?();
+  [computed2]?() {};
+  [1]?();
+  [2]?() {};
+  ["literal1"]?();
+  ["literal2"]?() {};
+  [obj.member]?() {};
+  [obj.member2]?();
+  [f()]?() {}
+}

packages/shared-fixtures/fixtures/typescript/basics/class-with-optional-computed-method.src.ts

@@ -1084,11 +1084,8 @@ export class Converter {
           }
         }
 
-        if (
-          result.key.type === AST_NODE_TYPES.Identifier &&
-          node.questionToken
-        ) {
-          result.key.optional = true;
+        if (node.questionToken) {
+          result.optional = true;
         }
 
         if (node.kind === SyntaxKind.GetAccessor) {

packages/typescript-estree/src/convert.ts

@@ -656,6 +656,7 @@ interface MethodDefinitionBase extends BaseNode {
   computed: boolean;
   static: boolean;
   kind: 'method' | 'get' | 'set' | 'constructor';
+  optional?: boolean;
   decorators?: Decorator[];
   accessibility?: Accessibility;
   typeParameters?: TSTypeParameterDeclaration;
@@ -682,6 +683,7 @@ interface PropertyBase extends BaseNode {
   computed: boolean;
   method: boolean;
   shorthand: boolean;
+  optional?: boolean;
   kind: 'init' | 'get' | 'set';
 }
 

packages/typescript-estree/src/ts-estree/ts-estree.ts

@@ -362,14 +362,6 @@ tester.addFixturePatternConfig('typescript/babylon-convergence', {
 tester.addFixturePatternConfig('typescript/basics', {
   fileType: 'ts',
   ignore: [
-    /**
-     * Babel and ts-estree reports optional field on different nodes
-     * TODO: investigate
-     */
-    'class-with-optional-methods',
-    'abstract-class-with-abstract-method',
-    'abstract-class-with-optional-method',
-    'declare-class-with-optional-method',
     /**
      * Babel parses it as TSQualifiedName
      * ts parses it as MemberExpression
@@ -399,7 +391,11 @@ tester.addFixturePatternConfig('typescript/basics', {
      * SyntaxError: 'abstract' modifier can only appear on a class, method, or property declaration.
      */
     'abstract-class-with-abstract-constructor',
-    // babel hard fails on computed string enum members, but TS doesn't
+    /**
+     * [BABEL ERRORED, BUT TS-ESTREE DID NOT]
+     * babel hard fails on computed string enum members, but TS doesn't
+     * TODO: report this to babel
+     */
     'export-named-enum-computed-string',
     /**
      * Babel: TSTypePredicate includes `:` statement in range

packages/typescript-estree/tests/ast-alignment/fixtures-to-test.ts

@@ -151,6 +151,16 @@ export function preprocessBabylonAST(ast: BabelTypes.File): any {
           };
         }
       },
+      MethodDefinition(node) {
+        /**
+         * Babel: MethodDefinition + abstract: true
+         * ts-estree: TSAbstractClassProperty
+         */
+        if (node.abstract) {
+          node.type = AST_NODE_TYPES.TSAbstractMethodDefinition;
+          delete node.abstract;
+        }
+      },
       ClassProperty(node) {
         /**
          * Babel: ClassProperty + abstract: true
@@ -198,6 +208,14 @@ export function preprocessBabylonAST(ast: BabelTypes.File): any {
           node.range[0] = node.typeParameters.range[0];
           node.loc.start = Object.assign({}, node.typeParameters.loc.start);
         }
+
+        /**
+         * ts-estree: if there's no body, it becomes a TSEmptyBodyFunctionExpression
+         */
+        if (!node.body) {
+          node.type = AST_NODE_TYPES.TSEmptyBodyFunctionExpression;
+          node.body = null;
+        }
       },
       /**
        * Template strings seem to also be affected by the difference in opinion between different parsers in

packages/typescript-estree/tests/ast-alignment/utils.ts

@@ -1781,6 +1781,8 @@ exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" e
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-with-mixin-reference.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
+exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-with-optional-computed-method.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
+
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-with-optional-computed-property.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;
 
 exports[`Parse all fixtures with "errorOnTypeScriptSyntacticAndSemanticIssues" enabled fixtures/typescript/basics/class-with-optional-methods.src 1`] = `"TEST OUTPUT: No semantic or syntactic issues found"`;