Extracted example

Author: unlight

src/example.ts

@@ -0,0 +1,11 @@
+export function hello(greet = 'world') {
+    return `hello ${greet}`;
+}
+
+it('hello world test', () => {
+    expect(hello()).toBe('hello world');
+});
+
+describe('hello world test', () => {
+    jest.mock('fs');
+});

src/index.spec.ts

@@ -1,6 +1,19 @@
 /* eslint-disable @typescript-eslint/tslint/config */
 import * as lib from './index';
+import * as ts from 'typescript';
 
-it('smoke', () => {
+type CreateFixtureArguments = {
+    sourceText: string;
+};
+
+function createFixture(createFixtureArguments: CreateFixtureArguments) {
+    const {
+        sourceText
+    } = createFixtureArguments;
+    ts.createSourceFile('filename.tsx', sourceText, ts.ScriptTarget.Latest);
+}
+
+it('smoke test', () => {
     expect(lib).toBeTruthy();
 });
+

src/index.ts

@@ -1,15 +1,18 @@
 import * as ts from 'typescript';
 
-function typescriptTransformUnspec<T extends ts.Node>(program: ts.Program): ts.TransformerFactory<T> {
-    return (context: ts.TransformationContext) => {
-        const visit: ts.Visitor = (node) => {
-            if (isSpecExpressionStatement(node)) {
-                return undefined;
-            }
-            return ts.visitEachChild(node, (child) => visit(child), context);
-        };
-        return (node) => ts.visitNode(node, visit);
-    };
+function typescriptTransformUnspec(program: ts.Program): ts.TransformerFactory<ts.SourceFile> {
+    return (context) => (file) => visitNodeAndChildren(file, program, context);
+}
+
+function visitNodeAndChildren(node: ts.Node, program: ts.Program, context: ts.TransformationContext): ts.SourceFile {
+    return ts.visitEachChild(visitNode(node), (childNode) => visitNodeAndChildren(childNode, program, context), context) as ts.SourceFile;
+}
+
+function visitNode(node: ts.Node): ts.Node | undefined {
+    if (isSpecExpressionStatement(node)) {
+        return undefined;
+    }
+    return node;
 }
 
 function isSpecExpressionStatement(node: ts.Node) {
@@ -18,13 +21,5 @@ function isSpecExpressionStatement(node: ts.Node) {
         && node.expression.expression.escapedText === 'it');
 }
 
-if (typeof it !== 'function') {
-    // @ts-ignore
-    var it: any = () => { };
-}
-it('smoke', () => {
-    expect(typescriptTransformUnspec).toBeTruthy();
-});
-
 module.exports = typescriptTransformUnspec;
 module.exports.default = typescriptTransformUnspec;

webpack.config.ts

@@ -1,11 +1,8 @@
 const unspecTransformer = require('./src/index');
 
 module.exports = async (options) => ({
-    externals: {
-        typescript: 'typescript',
-    },
     entry: {
-        lib: `${__dirname}/src/index.ts`,
+        example: `${__dirname}/src/example.ts`,
     },
     output: {
         path: `${__dirname}/dist`,