Chore: Build out AST comparison tests and categorize issues (#358)

Author: JamesHenry

tests/ast-alignment/known-issues.js

@@ -0,0 +1,88 @@
+/**
+ * ==================================================
+ * KNOWN/DIAGNOSED ISSUES
+ * ==================================================
+ */
+
+// const fixturePatternsToTest = [
+    /**
+     * "ExperimentalSpreadProperty" in espree/typescript-eslint-parser vs "SpreadElement" in Babylon
+     * comes up a lot in this section
+     */
+    // "ecma-features/experimentalObjectRestSpread/**/*.src.js", // mixture of babylon parse errors and AST diffs
+
+    /* ================================================== */
+
+    /**
+     * Template strings seem to also be affected by the difference in opinion between different parsers in:
+     * https://github.com/babel/babylon/issues/673
+     */
+    // "comments/no-comment-template.src.js", // Purely AST diffs
+    // "comments/template-string-block.src.js", // Purely AST diffs
+    // "ecma-features/templateStrings/**/*.src.js", // mixture of babylon parse errors and AST diffs
+
+    /* ================================================== */
+
+    /**
+     * TypeScript, espree and acorn parse this fine - esprima, flow and babylon do not...
+     */
+    // "ecma-features/forOf/for-of-with-function-initializer.src.js", // babylon parse errors
+
+    /* ================================================== */
+
+    /**
+     * TypeScript, flow and babylon parse this fine - esprima, espree and acorn do not...
+     */
+    // "ecma-features/modules/invalid-export-default.src.js",, // typescript-eslint-parser parse errors
+
+    /* ================================================== */
+
+    /**
+     * Babylon parse error because of more strict spec enforcement than other parsers.
+     */
+
+     /**
+     * super() is being used outside of constructor. Other parsers (e.g. espree, acorn) do not error on this.
+     */
+    // "ecma-features/classes/class-one-method-super.src.js", // babylon parse errors
+
+    /* ================================================== */
+
+    /**
+     * Expected babylon parse errors - all of these files below produce parse errors in espree
+     * as well, but the TypeScript compiler is so forgiving during parsing that typescript-eslint-parser
+     * does not actually error on them and will produce an AST.
+     */
+    // "ecma-features/arrowFunctions/error-dup-params.src.js", // babylon parse errors
+    // "ecma-features/arrowFunctions/error-dup-params.src.js", // babylon parse errors
+    // "ecma-features/arrowFunctions/error-strict-dup-params.src.js", // babylon parse errors
+    // "ecma-features/arrowFunctions/error-strict-octal.src.js", // babylon parse errors
+    // "ecma-features/arrowFunctions/error-two-lines.src.js", // babylon parse errors
+    // "ecma-features/classes/invalid-class-declaration.src.js", // babylon parse errors
+    // "ecma-features/classes/invalid-class-setter-declaration.src.js", // babylon parse errors
+    // "ecma-features/destructuring/invalid-defaults-object-assign.src.js", // babylon parse errors
+    // "ecma-features/destructuring-and-spread/error-complex-destructured-spread-first.src.js", // babylon parse errors
+    // "ecma-features/objectLiteralDuplicateProperties/error-proto-property.src.js", // babylon parse errors
+    // "ecma-features/objectLiteralDuplicateProperties/error-proto-string-property.src.js", // babylon parse errors
+    // "ecma-features/modules/invalid-export-named-default.src.js", // babylon parse errors
+    // "ecma-features/modules/invalid-import-default-module-specifier.src.js", // babylon parse errors
+    // "ecma-features/modules/invalid-import-module-specifier.src.js", // babylon parse errors
+    // "ecma-features/newTarget/invalid-new-target.src.js", // babylon parse errors
+    // "ecma-features/newTarget/invalid-unknown-property.src.js", // babylon parse errors
+    // "ecma-features/restParams/error-no-default.src.js", // babylon parse errors
+    // "ecma-features/restParams/error-not-last.src.js", // babylon parse errors
+    /**
+     * Deleting local variable in strict mode
+     */
+    // {
+    //     pattern: "ecma-features/modules/error-delete.src.js",
+    //     config: { babylonParserOptions: { sourceType: "module" } }
+    // },
+     /**
+     * 'with' in strict mode
+     */
+    // {
+    //     pattern: "ecma-features/modules/error-strict.src.js",
+    //     config: { babylonParserOptions: { sourceType: "module" } }
+    // },
+// ];

tests/ast-alignment/parse.js

@@ -13,9 +13,10 @@ function createError(message, line, column) { // eslint-disable-line
     return error;
 }
 
-function parseWithBabylonPluginTypescript(text) { // eslint-disable-line
+function parseWithBabylonPluginTypescript(text, parserOptions) { // eslint-disable-line
+    parserOptions = parserOptions || {};
     const babylon = require("babylon");
-    return babylon.parse(text, {
+    return babylon.parse(text, Object.assign({
         sourceType: "script",
         allowImportExportEverywhere: true,
         allowReturnOutsideFunction: true,
@@ -35,13 +36,14 @@ function parseWithBabylonPluginTypescript(text) { // eslint-disable-line
             "numericSeparator",
             "estree"
         ]
-    });
+    }, parserOptions));
 }
 
-function parseWithTypeScriptESLintParser(text) { // eslint-disable-line
+function parseWithTypeScriptESLintParser(text, parserOptions) { // eslint-disable-line
+    parserOptions = parserOptions || {};
     const parser = require("../../parser");
     try {
-        return parser.parse(text, {
+        return parser.parse(text, Object.assign({
             loc: true,
             range: true,
             tokens: false,
@@ -51,7 +53,7 @@ function parseWithTypeScriptESLintParser(text) { // eslint-disable-line
             ecmaFeatures: {
                 jsx: true
             }
-        });
+        }, parserOptions));
     } catch (e) {
         throw createError(
             e.message,
@@ -63,21 +65,26 @@ function parseWithTypeScriptESLintParser(text) { // eslint-disable-line
 
 module.exports = function parse(text, opts) {
 
-    let parseFunction;
-
-    switch (opts.parser) {
-        case "typescript-eslint-parser":
-            parseFunction = parseWithTypeScriptESLintParser;
-            break;
-        case "babylon-plugin-typescript":
-            parseFunction = parseWithBabylonPluginTypescript;
-            break;
-        default:
-            throw new Error("Please provide a valid parser: either \"typescript-eslint-parser\" or \"babylon-plugin-typescript\"");
-    }
+    /**
+     * Always return a consistent interface, there will be times when we expect both
+     * parsers to fail to parse the invalid source.
+     */
+    const result = {
+        parseError: null,
+        ast: null
+    };
 
     try {
-        return parseUtils.normalizeNodeTypes(parseFunction(text));
+        switch (opts.parser) {
+            case "typescript-eslint-parser":
+                result.ast = parseUtils.normalizeNodeTypes(parseWithTypeScriptESLintParser(text, opts.typeScriptESLintParserOptions));
+                break;
+            case "babylon-plugin-typescript":
+                result.ast = parseUtils.normalizeNodeTypes(parseWithBabylonPluginTypescript(text, opts.babylonParserOptions));
+                break;
+            default:
+                throw new Error("Please provide a valid parser: either \"typescript-eslint-parser\" or \"babylon-plugin-typescript\"");
+        }
     } catch (error) {
         const loc = error.loc;
         if (loc) {
@@ -86,7 +93,9 @@ module.exports = function parse(text, opts) {
             });
             error.message += `\n${error.codeFrame}`;
         }
-        throw error;
+        result.parseError = error;
     }
 
+    return result;
+
 };