default to spec mode for template literal transform (#6098)

* spec/loose/default switch for template literal transform, update/re-org tests

* update readme

* flip if statements

* consolidate else/if

* readme wording modification, updates to examples

packages/babel-plugin-transform-es2015-template-literals/README.md

@@ -13,7 +13,7 @@
 **Out**
 
 ```javascript
-"foo" + bar;
+"foo".concat(bar);
 ```
 
 ## Installation
@@ -42,8 +42,7 @@ With options:
 {
   "plugins": [
     ["transform-es2015-template-literals", {
-      "loose": true,
+      "loose": true
-      "spec": true
     }]
   ]
 }
@@ -69,22 +68,18 @@ require("babel-core").transform("code", {
 
 `boolean`, defaults to `false`.
 
-In loose mode, tagged template literal objects aren't frozen.
+When `true`, tagged template literal objects aren't frozen. All template literal expressions and quasis are combined with the `+` operator instead of with `String.prototype.concat`.
 
-### `spec`
+When `false` or not set, all template literal expressions and quasis are combined with `String.prototype.concat`. It will handle cases with `Symbol.toPrimitive` correctly and throw correctly if template literal expression is a `Symbol()`. See [babel/babel#5791](https://github.com/babel/babel/pull/5791).
-
-`boolean`, defaults to `false`.
-
-This option combines all template literal expressions and quasis with `String.prototype.concat`. It will handle cases with `Symbol.toPrimitive` correctly and throw correctly if template literal expression is a `Symbol()`. See [babel/babel#5791](https://github.com/babel/babel/pull/5791).
 
 **In**
 
 ```javascript
-`foo${bar}baz${quux}${1}`;
+`foo${bar}`;
 ```
 
 **Out**
 
 ```javascript
-"foo".concat(bar, "baz").concat(quux, 1);
+"foo" + bar;
 ```

packages/babel-plugin-transform-es2015-template-literals/src/index.js

@@ -75,20 +75,18 @@ export default function({ types: t }) {
         // since `+` is left-to-right associative
         // ensure the first node is a string if first/second isn't
         const considerSecondNode =
-          state.opts.spec || !t.isStringLiteral(nodes[1]);
+          !state.opts.loose || !t.isStringLiteral(nodes[1]);
         if (!t.isStringLiteral(nodes[0]) && considerSecondNode) {
           nodes.unshift(t.stringLiteral(""));
         }
         let root = nodes[0];
 
-        if (state.opts.spec) {
+        if (state.opts.loose) {
-          if (nodes.length > 1) {
-            root = buildConcatCallExressions(nodes);
-          }
-        } else {
           for (let i = 1; i < nodes.length; i++) {
             root = t.binaryExpression("+", root, nodes[i]);
           }
+        } else if (nodes.length > 1) {
+          root = buildConcatCallExressions(nodes);
         }
 
         path.replaceWith(root);

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/loose/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": [["transform-es2015-template-literals", {"loose": true}]]
+}

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/loose/tag/expected.js

@@ -0,0 +1,5 @@
+var _templateObject = _taggedTemplateLiteralLoose(["wow\na", "b ", ""], ["wow\\na", "b ", ""]);
+
+function _taggedTemplateLiteralLoose(strings, raw) { strings.raw = raw; return strings; }
+
+var foo = bar(_templateObject, 42, _.foobar());

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/normal/tag-loose/actual.js

@@ -1,3 +0,0 @@
-var foo = bar`wow\na${ 42 }b ${_.foobar()}`;
-var bar = bar`wow\nab${ 42 } ${_.foobar()}`;
-var bar = bar`wow\naB${ 42 } ${_.baz()}`;

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/normal/tag-loose/expected.js

@@ -1,9 +0,0 @@
-var _templateObject = _taggedTemplateLiteralLoose(["wow\na", "b ", ""], ["wow\\na", "b ", ""]),
-    _templateObject2 = _taggedTemplateLiteralLoose(["wow\nab", " ", ""], ["wow\\nab", " ", ""]),
-    _templateObject3 = _taggedTemplateLiteralLoose(["wow\naB", " ", ""], ["wow\\naB", " ", ""]);
-
-function _taggedTemplateLiteralLoose(strings, raw) { strings.raw = raw; return strings; }
-
-var foo = bar(_templateObject, 42, _.foobar());
-var bar = bar(_templateObject2, 42, _.foobar());
-var bar = bar(_templateObject3, 42, _.baz());

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/normal/tag-loose/options.json

@@ -1,3 +0,0 @@
-{
-  "plugins": [["transform-es2015-template-literals", { "loose": true }]]
-}

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/normal/tag/expected.js

@@ -1,5 +0,0 @@
-var _templateObject = _taggedTemplateLiteral(["wow\na", "b ", ""], ["wow\\na", "b ", ""]);
-
-function _taggedTemplateLiteral(strings, raw) { return Object.freeze(Object.defineProperties(strings, { raw: { value: Object.freeze(raw) } })); }
-
-var foo = bar(_templateObject, 42, _.foobar());

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/normal/template-revision-loose/options.json

@@ -1,3 +0,0 @@
-{
-  "plugins": [["transform-es2015-template-literals", { "loose": true }]]
-}

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/spec/options.json

@@ -1,3 +0,0 @@
-{
-  "plugins": [["transform-es2015-template-literals", { "spec": true }]]
-}

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/spec/template-revision/actual.js

@@ -1,13 +0,0 @@
-tag`\unicode and \u{55}`;
-
-tag`\01`;
-tag`\xg${0}right`;
-tag`left${0}\xg`;
-tag`left${0}\xg${1}right`;
-tag`left${0}\u000g${1}right`;
-tag`left${0}\u{-0}${1}right`;
-
-function a() {
-  var undefined = 4;
-  tag`\01`;
-}

packages/babel-plugin-transform-es2015-template-literals/test/fixtures/spec/template-revision/expected.js

@@ -1,22 +0,0 @@
-var _templateObject = _taggedTemplateLiteral([void 0], ["\\unicode and \\u{55}"]),
-    _templateObject2 = _taggedTemplateLiteral([void 0], ["\\01"]),
-    _templateObject3 = _taggedTemplateLiteral([void 0, "right"], ["\\xg", "right"]),
-    _templateObject4 = _taggedTemplateLiteral(["left", void 0], ["left", "\\xg"]),
-    _templateObject5 = _taggedTemplateLiteral(["left", void 0, "right"], ["left", "\\xg", "right"]),
-    _templateObject6 = _taggedTemplateLiteral(["left", void 0, "right"], ["left", "\\u000g", "right"]),
-    _templateObject7 = _taggedTemplateLiteral(["left", void 0, "right"], ["left", "\\u{-0}", "right"]);
-
-function _taggedTemplateLiteral(strings, raw) { return Object.freeze(Object.defineProperties(strings, { raw: { value: Object.freeze(raw) } })); }
-
-tag(_templateObject);
-tag(_templateObject2);
-tag(_templateObject3, 0);
-tag(_templateObject4, 0);
-tag(_templateObject5, 0, 1);
-tag(_templateObject6, 0, 1);
-tag(_templateObject7, 0, 1);
-
-function a() {
-  var undefined = 4;
-  tag(_templateObject2);
-}