docs: add example and organize files a bit

Author: danielpza

README.md

@@ -1,21 +1,27 @@
 <!--@[h1([pkg.name]), paragraph([pkg.description])]-->
+
 # typescript-transform-macros
 
 Typescript Transform Macros
+
 <!--/@-->
 
 <!--@shields("npm", "prettier", "ConventionalCommits", "spacemacs")-->
+
 [![npm version](https://img.shields.io/npm/v/typescript-transform-macros.svg)](https://www.npmjs.com/package/typescript-transform-macros) [![code style: prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square)](https://github.com/prettier/prettier) [![Conventional Commits](https://img.shields.io/badge/Conventional%20Commits-1.0.0-yellow.svg)](https://conventionalcommits.org) [![Built with Spacemacs](https://raw.githubusercontent.com/syl20bnr/spacemacs/master/assets/spacemacs-badge.svg?sanitize=true)](http://spacemacs.org)
+
 <!--/@-->
 
 Examples from <https://github.com/codemix/babel-plugin-macros>.
 
 <!--@installation()-->
+
 ## Installation
 
 ```sh
 npm install --save-dev typescript-transform-macros
 ```
+
 <!--/@-->
 
 ## Usage with [ttypescript](https://github.com/cevek/ttypescript/)
@@ -40,25 +46,11 @@ declare function MACRO<T>(t: T): T;
 
 _Input:_
 
-<!--@snippet("./src/__fixtures/input.ts")-->
+<!--@snippet("./examples/ttypescript/index.ts")-->
+
 ```ts
 declare function MACRO<T>(t: T): T;
 
-const FILTER = MACRO(
-  <T>(
-    inputConst: T[],
-    visitor: (value: T, index?: number, input?: T[]) => boolean
-  ) => {
-    const input = inputConst;
-    const length = input.length;
-    const result = [];
-    for (let i = 0; i < length; i++) {
-      if (visitor(input[i], i, input)) result.push(input[i]);
-    }
-    return result;
-  }
-);
-
 const MAP = MACRO(
   <T, L>(
     inputConst: T[],
@@ -74,34 +66,25 @@ const MAP = MACRO(
   }
 );
 
-function demo() {
-  return FILTER(MAP([1, 2, 3, 4], item => item + 1), v => v % 2 === 0);
-}
+console.log(MAP([1, 2, 3], n => 3 * n + 1));
 ```
+
 <!--/@-->
 
 _Output:_
 
-<!--@snippet("./src/__fixtures/expected.js")-->
+<!--@example("./examples/ttypescript/index.js")-->
+
 ```js
-function demo() {
-    const __input4 = [1, 2, 3, 4];
-    const __length4 = __input4.length;
-    const __result4 = new Array(__length4);
-    for (let __i4 = 0; __i4 < __length4; __i4++) {
-        __result4[__i4] =
-            __input4[__i4]
-                + 1;
-    }
-    const __input2 = __result4;
-    const __length2 = __input2.length;
-    const __result2 = [];
-    for (let __i2 = 0; __i2 < __length2; __i2++) {
-        if (__input2[__i2]
-            % 2 === 0)
-            __result2.push(__input2[__i2]);
-    }
-    return __result2;
+"use strict";
+const __input2 = [1, 2, 3];
+const __length2 = __input2.length;
+const __result2 = new Array(__length2);
+for (let __i2 = 0; __i2 < __length2; __i2++) {
+  __result2[__i2] = 3 * __input2[__i2] + 1;
 }
+console.log(__result2);
+//> [ 4, 7, 10 ]
 ```
+
 <!--/@-->

examples/ttypescript/.gitignore

@@ -0,0 +1 @@
+node_modules/

examples/ttypescript/index.js

@@ -0,0 +1,10 @@
+"use strict";
+const __input2 = [1, 2, 3];
+const __length2 = __input2.length;
+const __result2 = new Array(__length2);
+for (let __i2 = 0; __i2 < __length2; __i2++) {
+    __result2[__i2] =
+        3 *
+            __input2[__i2] + 1;
+}
+console.log(__result2);

examples/ttypescript/index.ts

@@ -0,0 +1,18 @@
+declare function MACRO<T>(t: T): T;
+
+const MAP = MACRO(
+  <T, L>(
+    inputConst: T[],
+    visitor: (value: T, index?: number, input?: T[]) => L
+  ) => {
+    const input = inputConst;
+    const length = input.length;
+    const result = new Array(length) as L[];
+    for (let i = 0; i < length; i++) {
+      result[i] = visitor(input[i], i, input);
+    }
+    return result;
+  }
+);
+
+console.log(MAP([1, 2, 3], n => 3 * n + 1));

examples/ttypescript/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "example-ttyepescript",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "build": "ttsc",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "devDependencies": {
+    "ttypescript": "^1.5.6",
+    "typescript": "^3.3.3333",
+    "typescript-transform-macros": "file:../.."
+  }
+}

examples/ttypescript/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "compilerOptions": {
+    "target": "esnext",
+    "module": "commonjs",
+    "strict": true,
+    "plugins": [{ "transform": "typescript-transform-macros" }],
+    "esModuleInterop": true
+  }
+}

src/__fixtures/expected.js src/__snapshots__/index.test.ts.snapsrc/__fixtures/expected.js renamed to src/__snapshots__/index.test.ts.snap

@@ -1,4 +1,7 @@
-function demo() {
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`transformer should compile 1`] = `
+"function demo() {
     const __input4 = [1, 2, 3, 4];
     const __length4 = __input4.length;
     const __result4 = new Array(__length4);
@@ -17,3 +20,5 @@ function demo() {
     }
     return __result2;
 }
+"
+`;

src/index.test.ts

@@ -1,15 +1,12 @@
 import * as ts from "typescript";
-import { readFileSync } from "fs";
 import { resolve } from "path";
 import transformer from "./";
 
 describe("transformer", () => {
   it("should compile", () => {
     const inputFile = resolve(__dirname, "__fixtures/input.ts");
-    const expectedFile = resolve(__dirname, "__fixtures/expected.js");
     const result = compile(inputFile);
-    const expected = readFileSync(expectedFile).toString();
-    expect(result).toBe(expected);
+    expect(result).toMatchSnapshot();
   });
 });
 

src/index.ts

@@ -13,6 +13,7 @@ class Transformer {
     const postExtract = ts.visitNode(node, this.extractMacros);
     return ts.visitNode(postExtract, this.resolveMacros);
   }
+  // Removes macro definition from code and save them for later
   private extractMacros = (node: ts.Node): ts.Node | undefined => {
     if (ts.isVariableStatement(node)) {
       const firstDeclaration = node.declarationList.declarations[0]; // TODO maybe check for more
@@ -35,6 +36,7 @@ class Transformer {
     }
     return ts.visitEachChild(node, this.extractMacros, this.context);
   };
+  // Search for macros calls and replace them with the macros
   private resolveMacros = (node: ts.Node): ts.Node | undefined => {
     if (ts.isBlock(node) || ts.isSourceFile(node)) {
       const newBlock = this.replaceMacros(node, this.rootMacros);
@@ -54,6 +56,7 @@ class Transformer {
     }
     return ts.visitEachChild(node, this.resolveMacros, this.context);
   };
+  // Prefix macros variables to avoid name collision, returns "return" expression
   private fixMacros = (
     node: ts.Block
   ): [ts.Expression | undefined, ts.Block] => {
@@ -84,12 +87,12 @@ class Transformer {
     const resultNode = ts.visitNode(node, visit);
     return [result, resultNode];
   };
+  // Actually replace the macros in the code
   private replaceMacros = (
     block: ts.BlockLike,
     macros: Macro[]
   ): ts.Statement[] => {
     const visit = (child: ts.Node): ts.Node => {
-      // TODO check if visit enought children
       if (ts.isBlock(child)) {
         return ts.createBlock(this.replaceMacros(child, macros));
       }