fix: use transform-tagged-template-literal plugin explicitly (#609)

Author: jayu

package.json

@@ -95,6 +95,7 @@
     "@babel/plugin-syntax-dynamic-import": "^7.8.3",
     "@babel/plugin-transform-modules-commonjs": "^7.9.0",
     "@babel/plugin-transform-runtime": "^7.9.0",
+    "@babel/plugin-transform-template-literals": "^7.8.3",
     "@babel/register": "^7.9.0",
     "@babel/template": "^7.8.6",
     "@babel/traverse": "^7.9.0",
@@ -138,4 +139,4 @@
       "<rootDir>/jest/resolveTypescript.js"
     ]
   }
-}
+}

src/__tests__/__snapshots__/preval.test.ts.snap

@@ -525,7 +525,7 @@ CSS:
    ;
 }
 
-Dependencies: @babel/runtime/helpers/interopRequireDefault, @babel/runtime/helpers/taggedTemplateLiteralLoose
+Dependencies: @babel/runtime/helpers/interopRequireDefault, @babel/runtime/helpers/taggedTemplateLiteral
 
 `;
 

src/babel/evaluators/buildOptions.ts

@@ -1,5 +1,5 @@
 /**
- * This file handles preparing babel config for Linaria babel plugin.
+ * This file handles preparing babel config for Linaria preevaluation.
  */
 
 import { PluginItem, TransformOptions } from '@babel/core';

src/babel/evaluators/extractor/index.ts

@@ -51,6 +51,18 @@ const extractor: Evaluator = (filename, options, text, only = null) => {
     { useESModules: false },
   ]);
 
+  // We made a mistake somewhen, and linaria preval was dependent on `plugin-transform-template-literals`
+  // Usually it was loaded into preval, because user was using `@babel/preset-env` preset which included that plugin. Internally we used this preset for tests (and previously for everything) - thats why we implemented behavior based on existing of that plugin
+  // The ordering is very important here, that's why it is added as a preset, not just as a plugin. It makes this plugin run *AFTER* linaria preset, which is required to make have the current behavior.
+  // In preval we have 2 visitors, one for Call Expressions and second for TaggedTemplateLiterals. Babel process TaggedTemplates first for some reason, and we grab only the css`` statements, we skip styled statements at this stage.
+  // Then it process TaggedTemplateLiterals with mentioned plugin, which transforms them to CallExpressions (babel seems to apply thw whole set of plugins for particular visitor, then for the next visitor and so on).
+  // Then Linaria can identify all `styled` as call expressions, including `styled.h1`, `styled.p` and others.
+
+  // Presets ordering is from last to first, so we add the plugin at the beginning of the list, which persist the order that was established with formerly used `@babel/preset-env`.
+
+  transformOptions.presets!.unshift({
+    plugins: ['@babel/plugin-transform-template-literals'],
+  });
   // Expressions will be extracted only for __linariaPreval.
   // In all other cases a code will be returned as is.
   let { code } = transformSync(text, transformOptions)!;

src/babel/evaluators/preeval.ts

@@ -5,11 +5,11 @@
 import { NodePath } from '@babel/traverse';
 import { types } from '@babel/core';
 import GenerateClassNames from '../visitors/GenerateClassNames';
-import JSXElement from '../visitors/JSXElement';
-import CallExpression from '../visitors/CallExpression';
+import DetectStyledImportName from '../visitors/DetectStyledImportName';
+import JSXElement from './visitors/JSXElement';
+import ProcessStyled from './visitors/ProcessStyled';
+import ProcessCSS from './visitors/ProcessCSS';
 import { State, StrictOptions } from '../types';
-import CSSTemplateExpression from '../visitors/CSSTemplateExpression';
-import ImportDeclaration from '../visitors/ImportDeclaration';
 
 function preeval(_babel: any, options: StrictOptions) {
   return {
@@ -26,16 +26,15 @@ function preeval(_babel: any, options: StrictOptions) {
           // We need our transforms to run before anything else
           // So we traverse here instead of a in a visitor
           path.traverse({
-            ImportDeclaration: p => ImportDeclaration(p, state),
+            ImportDeclaration: p => DetectStyledImportName(p, state),
             TaggedTemplateExpression: p =>
               GenerateClassNames(p, state, options),
-
             JSXElement,
           });
         },
       },
-      CallExpression,
-      TaggedTemplateExpression: CSSTemplateExpression,
+      CallExpression: ProcessStyled,
+      TaggedTemplateExpression: ProcessCSS, // TaggedTemplateExpression is processed before CallExpression
     },
   };
 }

src/babel/evaluators/shaker/index.ts

@@ -15,7 +15,11 @@ function prepareForShake(
   transformOptions.ast = true;
   transformOptions.presets!.unshift([
     '@babel/preset-env',
-    { targets: 'ie 11' },
+    {
+      targets: 'ie 11',
+      // we need this plugin so we list it explicitly, explanation in `evaluators/extractor/index`
+      include: ['@babel/plugin-transform-template-literals'],
+    },
   ]);
   transformOptions.presets!.unshift([require.resolve('../preeval'), options]);
   transformOptions.plugins!.unshift('transform-react-remove-prop-types');

src/babel/visitors/JSXElement.ts …/babel/evaluators/visitors/JSXElement.tssrc/babel/visitors/JSXElement.ts renamed to src/babel/evaluators/visitors/JSXElement.ts src/babel/visitors/JSXElement.ts renamed to src/babel/evaluators/visitors/JSXElement.ts

@@ -1,10 +1,13 @@
+/**
+ * This visitor replaces css tag with the generated className
+ *
+ */
+
 import { NodePath } from '@babel/traverse';
 import { types as t } from '@babel/core';
-import getLinariaComment from '../utils/getLinariaComment';
+import getLinariaComment from '../../utils/getLinariaComment';
 
-export default function CSSTemplateExpression(
-  path: NodePath<t.TaggedTemplateExpression>
-) {
+export default function ProcessCSS(path: NodePath<t.TaggedTemplateExpression>) {
   if (t.isIdentifier(path.node.tag) && path.node.tag.name === 'css') {
     const [, , className] = getLinariaComment(path);
     if (!className) {

…/babel/visitors/CSSTemplateExpression.ts …/babel/evaluators/visitors/ProcessCSS.tssrc/babel/visitors/CSSTemplateExpression.ts renamed to src/babel/evaluators/visitors/ProcessCSS.ts src/babel/visitors/CSSTemplateExpression.ts renamed to src/babel/evaluators/visitors/ProcessCSS.ts

@@ -1,6 +1,15 @@
+/**
+ * This visitor replaces styled components with metadata about them.
+ * CallExpression should be used to match styled components.
+ * Works out of the box for styled that wraps other component,
+ * styled.tagName are transformed to call expressions using @babel/plugin-transform-template-literals
+ * @babel/plugin-transform-template-literals is loaded as a prest, to force proper ordering. It has to run just after linaria.
+ * It is used explicitly in extractor, and loaded as a part of `prest-env` in shaker
+ */
+
 import { NodePath } from '@babel/traverse';
 import { types } from '@babel/core';
-import getLinariaComment from '../utils/getLinariaComment';
+import getLinariaComment from '../../utils/getLinariaComment';
 import { expression } from '@babel/template';
 
 const linariaComponentTpl = expression(
@@ -13,7 +22,7 @@ const linariaComponentTpl = expression(
   }`
 );
 
-export default function CallExpression(path: NodePath<types.CallExpression>) {
+export default function ProcessStyled(path: NodePath<types.CallExpression>) {
   const [, displayName, className] = getLinariaComment(path);
   if (!className) {
     return;

src/babel/visitors/CallExpression.ts …bel/evaluators/visitors/ProcessStyled.tssrc/babel/visitors/CallExpression.ts renamed to src/babel/evaluators/visitors/ProcessStyled.ts src/babel/visitors/CallExpression.ts renamed to src/babel/evaluators/visitors/ProcessStyled.ts

@@ -26,9 +26,9 @@ import {
   ValueCache,
 } from './types';
 import CollectDependencies from './visitors/CollectDependencies';
-import ImportDeclaration from './visitors/ImportDeclaration';
-import { debug } from './utils/logger';
+import DetectStyledImportName from './visitors/DetectStyledImportName';
 import GenerateClassNames from './visitors/GenerateClassNames';
+import { debug } from './utils/logger';
 
 function isLazyValue(v: ExpressionValue): v is LazyValue {
   return v.kind === ValueType.LAZY;
@@ -113,7 +113,7 @@ export default function extract(_babel: any, options: StrictOptions) {
           // We need our transforms to run before anything else
           // So we traverse here instead of a in a visitor
           path.traverse({
-            ImportDeclaration: p => ImportDeclaration(p, state),
+            ImportDeclaration: p => DetectStyledImportName(p, state),
             TaggedTemplateExpression: p => {
               GenerateClassNames(p, state, options);
               CollectDependencies(p, state, options);
@@ -186,13 +186,11 @@ export default function extract(_babel: any, options: StrictOptions) {
         },
         exit(_: any, state: State) {
           if (Object.keys(state.rules).length) {
-            // Store the result as the file metadata
-            state.file.metadata = {
-              linaria: {
-                rules: state.rules,
-                replacements: state.replacements,
-                dependencies: state.dependencies,
-              },
+            // Store the result as the file metadata under linaria key
+            state.file.metadata.linaria = {
+              rules: state.rules,
+              replacements: state.replacements,
+              dependencies: state.dependencies,
             };
           }