Solves Tagged template literal size optimization (#7379)

* Tagged template literal size optimization
solves #7352

* Incorporates review changes

packages/babel-helpers/src/helpers.js

@@ -690,6 +690,7 @@ helpers.slicedToArrayLoose = defineHelper(`
 
 helpers.taggedTemplateLiteral = defineHelper(`
   export default function _taggedTemplateLiteral(strings, raw) {
+    if (!raw) { raw = strings.slice(0); }
     return Object.freeze(Object.defineProperties(strings, {
         raw: { value: Object.freeze(raw) }
     }));
@@ -698,6 +699,7 @@ helpers.taggedTemplateLiteral = defineHelper(`
 
 helpers.taggedTemplateLiteralLoose = defineHelper(`
   export default function _taggedTemplateLiteralLoose(strings, raw) {
+    if (!raw) { raw = strings.slice(0); }
     strings.raw = raw;
     return strings;
   }

packages/babel-plugin-transform-modules-commonjs/test/fixtures/interop-loose/imports-hoisting/output.js

@@ -1,5 +1,5 @@
 var _taggedTemplateLiteral = require("@babel/runtime/helpers/taggedTemplateLiteral");
 
-var _templateObject = /*#__PURE__*/ _taggedTemplateLiteral(["foo"], ["foo"]);
+var _templateObject = /*#__PURE__*/ _taggedTemplateLiteral(["foo"]);
 
 tag(_templateObject);

packages/babel-plugin-transform-modules-commonjs/test/fixtures/interop/imports-hoisting/output.js

@@ -1,5 +1,5 @@
 var _taggedTemplateLiteral = require("@babel/runtime/helpers/taggedTemplateLiteral");
 
-var _templateObject = /*#__PURE__*/ _taggedTemplateLiteral(["foo"], ["foo"]);
+var _templateObject = /*#__PURE__*/ _taggedTemplateLiteral(["foo"]);
 
 tag(_templateObject);

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

@@ -54,6 +54,9 @@ export default function(api, options) {
         const strings = [];
         const raws = [];
 
+        // Flag variable to check if contents of strings and raw are equal
+        let isStringsRawEqual = true;
+
         for (const elem of (quasi.quasis: Array)) {
           const { raw, cooked } = elem.value;
           const value =
@@ -63,6 +66,11 @@ export default function(api, options) {
 
           strings.push(value);
           raws.push(t.stringLiteral(raw));
+
+          if (raw !== cooked) {
+            // false even if one of raw and cooked are not equal
+            isStringsRawEqual = false;
+          }
         }
 
         // Generate a unique name based on the string literals so we dedupe
@@ -81,10 +89,15 @@ export default function(api, options) {
           this.templates.set(name, templateObject);
 
           const helperId = this.addHelper(helperName);
-          const init = t.callExpression(helperId, [
+          const callExpressionInput = [];
-            t.arrayExpression(strings),
+          callExpressionInput.push(t.arrayExpression(strings));
-            t.arrayExpression(raws),
+
-          ]);
+          if (!isStringsRawEqual) {
+            callExpressionInput.push(t.arrayExpression(raws));
+          }
+
+          // only add raw arrayExpression if there is any difference between raws and strings
+          const init = t.callExpression(helperId, callExpressionInput);
           annotateAsPure(init);
           init._compact = true;
           programPath.scope.push({

packages/babel-plugin-transform-template-literals/test/fixtures/default/simple-tag/input.js

@@ -0,0 +1,2 @@
+var foo = tag`wow`;
+var bar = tag`first${1}second`;

packages/babel-plugin-transform-template-literals/test/fixtures/default/simple-tag/output.js

@@ -0,0 +1,7 @@
+var _templateObject = /*#__PURE__*/ _taggedTemplateLiteral(["wow"]),
+    _templateObject2 = /*#__PURE__*/ _taggedTemplateLiteral(["first", "second"]);
+
+function _taggedTemplateLiteral(strings, raw) { if (!raw) { raw = strings.slice(0); } return Object.freeze(Object.defineProperties(strings, { raw: { value: Object.freeze(raw) } })); }
+
+var foo = tag(_templateObject);
+var bar = tag(_templateObject2, 1);

packages/babel-plugin-transform-template-literals/test/fixtures/default/tag/output.js

@@ -2,7 +2,7 @@ var _templateObject = /*#__PURE__*/ _taggedTemplateLiteral(["wow\na", "b ", ""],
     _templateObject2 = /*#__PURE__*/ _taggedTemplateLiteral(["wow\nab", " ", ""], ["wow\\nab", " ", ""]),
     _templateObject3 = /*#__PURE__*/ _taggedTemplateLiteral(["wow\naB", " ", ""], ["wow\\naB", " ", ""]);
 
-function _taggedTemplateLiteral(strings, raw) { return Object.freeze(Object.defineProperties(strings, { raw: { value: Object.freeze(raw) } })); }
+function _taggedTemplateLiteral(strings, raw) { if (!raw) { raw = strings.slice(0); } return Object.freeze(Object.defineProperties(strings, { raw: { value: Object.freeze(raw) } })); }
 
 var foo = bar(_templateObject, 42, _.foobar());
 var bar = bar(_templateObject2, 42, _.foobar());

packages/babel-plugin-transform-template-literals/test/fixtures/default/template-revision/output.js

@@ -6,7 +6,7 @@ var _templateObject = /*#__PURE__*/ _taggedTemplateLiteral([void 0], ["\\unicode
     _templateObject6 = /*#__PURE__*/ _taggedTemplateLiteral(["left", void 0, "right"], ["left", "\\u000g", "right"]),
     _templateObject7 = /*#__PURE__*/ _taggedTemplateLiteral(["left", void 0, "right"], ["left", "\\u{-0}", "right"]);
 
-function _taggedTemplateLiteral(strings, raw) { return Object.freeze(Object.defineProperties(strings, { raw: { value: Object.freeze(raw) } })); }
+function _taggedTemplateLiteral(strings, raw) { if (!raw) { raw = strings.slice(0); } return Object.freeze(Object.defineProperties(strings, { raw: { value: Object.freeze(raw) } })); }
 
 tag(_templateObject);
 tag(_templateObject2);

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

@@ -2,7 +2,7 @@ var _templateObject = /*#__PURE__*/ _taggedTemplateLiteralLoose(["wow\na", "b ",
     _templateObject2 = /*#__PURE__*/ _taggedTemplateLiteralLoose(["wow\nab", " ", ""], ["wow\\nab", " ", ""]),
     _templateObject3 = /*#__PURE__*/ _taggedTemplateLiteralLoose(["wow\naB", " ", ""], ["wow\\naB", " ", ""]);
 
-function _taggedTemplateLiteralLoose(strings, raw) { strings.raw = raw; return strings; }
+function _taggedTemplateLiteralLoose(strings, raw) { if (!raw) { raw = strings.slice(0); } strings.raw = raw; return strings; }
 
 var foo = bar(_templateObject, 42, _.foobar());
 var bar = bar(_templateObject2, 42, _.foobar());

packages/babel-plugin-transform-template-literals/test/fixtures/loose/template-revision/output.js

@@ -6,7 +6,7 @@ var _templateObject = /*#__PURE__*/ _taggedTemplateLiteralLoose([void 0], ["\\un
     _templateObject6 = /*#__PURE__*/ _taggedTemplateLiteralLoose(["left", void 0, "right"], ["left", "\\u000g", "right"]),
     _templateObject7 = /*#__PURE__*/ _taggedTemplateLiteralLoose(["left", void 0, "right"], ["left", "\\u{-0}", "right"]);
 
-function _taggedTemplateLiteralLoose(strings, raw) { strings.raw = raw; return strings; }
+function _taggedTemplateLiteralLoose(strings, raw) { if (!raw) { raw = strings.slice(0); } strings.raw = raw; return strings; }
 
 tag(_templateObject);
 tag(_templateObject2);