add babel-template package

packages/babel-template/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "babel-template",
+  "version": "5.8.22",
+  "description": "",
+  "author": "Sebastian McKenzie <sebmck@gmail.com>",
+  "homepage": "https://babeljs.io/",
+  "license": "MIT",
+  "repository": "babel/babel",
+  "main": "lib/index.js",
+  "dependencies": {
+    "babylon": "^5.8.20",
+    "babel-traverse": "^5.8.22",
+    "babel-types": "^5.8.22",
+    "lodash": "^3.10.1"
+  }
+}

packages/babel-template/src/index.js

@@ -0,0 +1,78 @@
+import cloneDeep from "lodash/lang/cloneDeep";
+import isEmpty from "lodash/lang/isEmpty";
+import has from "lodash/object/has";
+import traverse from "babel-traverse";
+import * as babylon from "babylon";
+import * as t from "babel-types";
+
+export default function (code) {
+  var stack = new Error().stack.split("\n").slice(1).join("\n");
+
+  var getAst = function () {
+    try {
+      var ast = babylon.parse(code, {
+        allowReturnOutsideFunction: true
+      }).program;
+
+      ast = traverse.removeProperties(ast);
+    } catch (err) {
+      err.stack = `${err.stack}from\n${stack}`;
+    }
+
+    getAst = function () {
+      return ast;
+    };
+
+    return ast;
+  };
+
+  return function (nodes, keepExpression) {
+    return useTemplate(getAst(), nodes, keepExpression);
+  };
+}
+
+function useTemplate(ast, nodes?: Array<Object>, keepExpression?: boolean) {
+  if (nodes === true) {
+    keepExpression = true;
+    nodes = null;
+  }
+
+  ast = cloneDeep(ast);
+
+  if (!isEmpty(nodes)) {
+    traverse(ast, templateVisitor, null, nodes);
+  }
+
+  if (ast.body.length > 1) {
+    return ast.body;
+  }
+
+  var node = ast.body[0];
+  if (!keepExpression && t.isExpressionStatement(node)) {
+    return node.expression;
+  } else {
+    return node;
+  }
+}
+
+var templateVisitor = {
+  // 360
+  noScope: true,
+
+  enter(path, nodes) {
+    var { node } = path;
+
+    if (t.isExpressionStatement(node)) {
+      node = node.expression;
+    }
+
+    if (t.isIdentifier(node) && has(nodes, node.name)) {
+      path.skip();
+      path.replaceInline(nodes[node.name]);
+    }
+  },
+
+  exit({ node }) {
+    traverse.clearNode(node);
+  }
+};