add jsx and tsx parsers

Author: lobsterkatie

packages/nextjs/src/config/loaders/parsers.ts

@@ -0,0 +1,64 @@
+/**
+ * Note: The implementation here is loosely based on the jsx and tsx parsers in 'jscodeshift'. It doesn't expose its
+ * parsers, so we have to provide our own if we want to use anything besides the default. Fortunately, its parsers turn
+ * out to just be wrappers around `babel.parse` with certain options set. The options chosen here are different from the
+ * `jscodeshift` parsers in that a) unrecognized and deprecated options and options set to default values have been
+ * removed, and b) all standard plugins are included, meaning the widest range of user code is able to be parsed.
+ */
+
+import * as babel from '@babel/parser';
+import { File } from '@babel/types';
+
+type Parser = {
+  parse: (code: string) => babel.ParseResult<File>;
+};
+
+const jsxOptions: babel.ParserOptions = {
+  // Nextjs supports dynamic import, so this seems like a good idea
+  allowImportExportEverywhere: true,
+  // We're only supporting wrapping in ESM pages
+  sourceType: 'module',
+  // Without `tokens`, jsx parsing breaks
+  tokens: true,
+  // The maximal set of non-mutually-exclusive standard plugins, so as to support as much weird syntax in our users'
+  // code as possible
+  plugins: [
+    'asyncDoExpressions',
+    'decimal',
+    ['decorators', { decoratorsBeforeExport: false }],
+    'decoratorAutoAccessors',
+    'destructuringPrivate',
+    'doExpressions',
+    'estree',
+    'exportDefaultFrom',
+    'functionBind',
+    'importMeta',
+    'importAssertions',
+    'jsx',
+    'moduleBlocks',
+    'partialApplication',
+    ['pipelineOperator', { proposal: 'hack', topicToken: '^' }],
+    'regexpUnicodeSets',
+    'throwExpressions',
+  ] as babel.ParserPlugin[],
+};
+
+const tsxOptions = {
+  ...jsxOptions,
+  // Because `jsxOptions` is typed as a `ParserOptions` object, TS doesn't discount the possibility of its `plugins`
+  // property being undefined, even though it is, in fact, very clearly defined - hence the empty array.
+  plugins: [...(jsxOptions.plugins || []), 'typescript'] as babel.ParserPlugin[],
+};
+
+/**
+ * Create either a jsx or tsx parser to be used by `jscodeshift`.
+ *
+ * @param type Either 'jsx' or 'tsx'
+ * @returns An object with the appropriate `parse` method.
+ */
+export function makeParser(type: 'jsx' | 'tsx'): Parser {
+  const options = type === 'jsx' ? jsxOptions : tsxOptions;
+  return {
+    parse: code => babel.parse(code, options),
+  };
+}