feat: add errorOnTypeScriptSyntaticAndSemanticIssues option (#57)

Author: JamesHenry

src/ast-converter.ts

@@ -5,25 +5,12 @@
  * @copyright jQuery Foundation and other contributors, https://jquery.org/
  * MIT License
  */
-import convert, { getASTMaps, resetASTMaps } from './convert';
+import convert, { getASTMaps, resetASTMaps, convertError } from './convert';
 import { convertComments } from './convert-comments';
 import nodeUtils from './node-utils';
 import ts from 'typescript';
 import { Extra } from './temp-types-based-on-js-source';
 
-/**
- * Extends and formats a given error object
- * @param  {Object} error the error object
- * @returns {Object}       converted error object
- */
-function convertError(error: any) {
-  return nodeUtils.createError(
-    error.file,
-    error.start,
-    error.message || error.messageText
-  );
-}
-
 export default (
   ast: ts.SourceFile,
   extra: Extra,

src/convert.ts

@@ -39,6 +39,19 @@ interface ConvertConfig {
   additionalOptions: ConvertAdditionalOptions;
 }
 
+/**
+ * Extends and formats a given error object
+ * @param  {Object} error the error object
+ * @returns {Object}       converted error object
+ */
+export function convertError(error: any) {
+  return nodeUtils.createError(
+    error.file,
+    error.start,
+    error.message || error.messageText
+  );
+}
+
 /**
  * Converts a TypeScript node into an ESTree node
  * @param  {Object} config configuration options for the conversion

src/parser.ts

@@ -12,14 +12,16 @@ import {
 import semver from 'semver';
 import ts from 'typescript';
 import convert from './ast-converter';
+import { convertError } from './convert';
+import { Program } from './estree/spec';
+import util from './node-utils';
 import {
-  Extra,
-  ParserOptions,
+  ESTreeComment,
   ESTreeToken,
-  ESTreeComment
+  Extra,
+  ParserOptions
 } from './temp-types-based-on-js-source';
-import { Program } from './estree/spec';
-import util from './node-utils';
+import { getFirstSemanticOrSyntacticError } from './semantic-errors';
 
 const packageJSON = require('../package.json');
 
@@ -59,6 +61,7 @@ function resetExtra(): void {
     log: console.log,
     projects: [],
     errorOnUnknownASTType: false,
+    errorOnTypeScriptSyntaticAndSemanticIssues: false,
     code: '',
     tsconfigRootDir: process.cwd(),
     extraFileExtensions: []
@@ -246,6 +249,18 @@ function generateAST<T extends ParserOptions = ParserOptions>(
       extra.errorOnUnknownASTType = true;
     }
 
+    /**
+     * Retrieve semantic and syntactic diagnostics from the underlying TypeScript Program
+     * and turn them into parse errors
+     */
+    if (
+      shouldGenerateServices &&
+      typeof options.errorOnTypeScriptSyntaticAndSemanticIssues === 'boolean' &&
+      options.errorOnTypeScriptSyntaticAndSemanticIssues
+    ) {
+      extra.errorOnTypeScriptSyntaticAndSemanticIssues = true;
+    }
+
     if (typeof options.useJSXTextNode === 'boolean' && options.useJSXTextNode) {
       extra.useJSXTextNode = true;
     }
@@ -304,7 +319,23 @@ function generateAST<T extends ParserOptions = ParserOptions>(
   );
 
   extra.code = code;
+
+  /**
+   * Convert the AST
+   */
   const { estree, astMaps } = convert(ast, extra, shouldProvideParserServices);
+
+  /**
+   * Even if TypeScript parsed the source code ok, and we had no problems converting the AST,
+   * there may be other syntactic or semantic issues in the code that we can optionally report on.
+   */
+  if (program && extra.errorOnTypeScriptSyntaticAndSemanticIssues) {
+    const error = getFirstSemanticOrSyntacticError(program, ast);
+    if (error) {
+      throw convertError(error);
+    }
+  }
+
   return {
     estree,
     program: shouldProvideParserServices ? program : undefined,
@@ -327,6 +358,11 @@ export function parse<T extends ParserOptions = ParserOptions>(
   code: string,
   options?: T
 ) {
+  if (options && options.errorOnTypeScriptSyntaticAndSemanticIssues) {
+    throw new Error(
+      `"errorOnTypeScriptSyntaticAndSemanticIssues" is only supported for parseAndGenerateServices()`
+    );
+  }
   return generateAST<T>(code, options).estree;
 }
 

src/semantic-errors.ts

@@ -0,0 +1,59 @@
+import ts from 'typescript';
+
+interface SemanticOrSyntacticError extends ts.Diagnostic {
+  message: string;
+}
+
+/**
+ * By default, diagnostics from the TypeScript compiler contain all errors - regardless of whether
+ * they are related to generic ECMAScript standards, or TypeScript-specific constructs.
+ *
+ * Therefore, we filter out all diagnostics, except for the ones we explicitly want to consider when
+ * the user opts in to throwing errors on semantic issues.
+ */
+export function getFirstSemanticOrSyntacticError(
+  program: ts.Program,
+  ast: ts.SourceFile
+): SemanticOrSyntacticError | undefined {
+  const supportedSyntacticDiagnostics = whitelistSupportedDiagnostics(
+    program.getSyntacticDiagnostics(ast)
+  );
+  if (supportedSyntacticDiagnostics.length) {
+    return convertDiagnosticToSemanticOrSyntacticError(
+      supportedSyntacticDiagnostics[0]
+    );
+  }
+  const supportedSemanticDiagnostics = whitelistSupportedDiagnostics(
+    program.getSemanticDiagnostics(ast)
+  );
+  if (supportedSemanticDiagnostics.length) {
+    return convertDiagnosticToSemanticOrSyntacticError(
+      supportedSemanticDiagnostics[0]
+    );
+  }
+  return undefined;
+}
+
+function whitelistSupportedDiagnostics(
+  diagnostics: ReadonlyArray<ts.DiagnosticWithLocation | ts.Diagnostic>
+): ReadonlyArray<ts.DiagnosticWithLocation | ts.Diagnostic> {
+  return diagnostics.filter(diagnostic => {
+    switch (diagnostic.code) {
+      case 1123: // ts 3.2: "Variable declaration list cannot be empty."
+        return true;
+    }
+    return false;
+  });
+}
+
+function convertDiagnosticToSemanticOrSyntacticError(
+  diagnostic: ts.Diagnostic
+): SemanticOrSyntacticError {
+  return {
+    ...diagnostic,
+    message: ts.flattenDiagnosticMessageText(
+      diagnostic.messageText,
+      ts.sys.newLine
+    )
+  };
+}

src/temp-types-based-on-js-source.ts

@@ -58,6 +58,7 @@ export interface ESTreeNodeLoc {
 
 export interface Extra {
   errorOnUnknownASTType: boolean;
+  errorOnTypeScriptSyntaticAndSemanticIssues: boolean;
   useJSXTextNode: boolean;
   tokens: null | ESTreeToken[];
   comment: boolean;
@@ -80,6 +81,7 @@ export interface ParserOptions {
   comment?: boolean;
   jsx?: boolean;
   errorOnUnknownASTType?: boolean;
+  errorOnTypeScriptSyntaticAndSemanticIssues?: boolean;
   useJSXTextNode?: boolean;
   loggerFn?: Function | false;
   project?: string | string[];

tests/ast-alignment/fixtures-to-test.ts

@@ -190,7 +190,8 @@ let fixturePatternConfigsToTest = [
        * as well, but the TypeScript compiler is so forgiving during parsing that typescript-estree
        * does not actually error on them and will produce an AST.
        */
-      'error-complex-destructured-spread-first' // babel parse errors
+      'error-complex-destructured-spread-first', // babel parse errors
+      'not-final-array' // babel parse errors
     ]
   }),
 
@@ -446,7 +447,8 @@ let fixturePatternConfigsToTest = [
       'decorator-on-enum-declaration', // babel parse errors
       'decorator-on-interface-declaration', // babel parse errors
       'interface-property-modifiers', // babel parse errors
-      'enum-with-keywords' // babel parse errors
+      'enum-with-keywords', // babel parse errors
+      'solo-const' // babel parse errors
     ]
   }),
 

tests/fixtures/javascript/destructuring-and-defaultParams/param-object-wrapped.src.xjs renamed to tests/fixtures/javascript/destructuring-and-defaultParams/param-object-wrapped.src.js

@@ -0,0 +1 @@
+const