add pure ignore comment for css modules

Author: jantimon

src/index.js

@@ -4,6 +4,8 @@ const selectorParser = require("postcss-selector-parser");
 const valueParser = require("postcss-value-parser");
 const { extractICSS } = require("icss-utils");
 
+const IGNORE_MARKER = "cssmodules-pure-ignore";
+
 const isSpacing = (node) => node.type === "combinator" && node.value === " ";
 
 function normalizeNodeArray(nodes) {
@@ -26,6 +28,8 @@ function normalizeNodeArray(nodes) {
 }
 
 function localizeNode(rule, mode, localAliasMap) {
+  const isIgnored = hasIgnoreComment(rule);
+
   const transform = (node, context) => {
     if (context.ignoreNextSpacing && !isSpacing(node)) {
       throw new Error("Missing whitespace after " + context.ignoreNextSpacing);
@@ -212,6 +216,10 @@ function localizeNode(rule, mode, localAliasMap) {
           break;
         }
 
+        if (isIgnored) {
+          break;
+        }
+
         const isImportedValue = localAliasMap.has(node.value);
         const isImportedWithExplicitScope = isImportedValue && context.explicit;
 
@@ -348,6 +356,10 @@ function localizeDeclarationValues(localize, declaration, context) {
 }
 
 function localizeDeclaration(declaration, context) {
+  if (hasIgnoreComment(declaration)) {
+    return;
+  }
+
   const isAnimation = /animation$/i.test(declaration.prop);
 
   if (isAnimation) {
@@ -471,6 +483,22 @@ function localizeDeclaration(declaration, context) {
   }
 }
 
+function hasIgnoreComment(node) {
+  if (!node.parent) {
+    return false;
+  }
+  const indexInParent = node.parent.index(node);
+  for (let i = indexInParent - 1; i >= 0; i--) {
+    const prevNode = node.parent.nodes[i];
+    if (prevNode.type === "comment") {
+      return prevNode.text.trimStart().startsWith(IGNORE_MARKER)
+    } else {
+      break;
+    }
+  }
+  return false;
+}
+
 module.exports = (options = {}) => {
   if (
     options &&
@@ -554,7 +582,11 @@ module.exports = (options = {}) => {
                     context.options = options;
                     context.localAliasMap = localAliasMap;
 
-                    if (pureMode && context.hasPureGlobals) {
+                    if (
+                      pureMode &&
+                      context.hasPureGlobals &&
+                      !hasIgnoreComment(selector)
+                    ) {
                       throw atRule.error(
                         'Selector in at-rule"' +
                           selector +
@@ -605,7 +637,7 @@ module.exports = (options = {}) => {
             context.options = options;
             context.localAliasMap = localAliasMap;
 
-            if (pureMode && context.hasPureGlobals) {
+            if (pureMode && context.hasPureGlobals && !hasIgnoreComment(rule)) {
               throw rule.error(
                 'Selector "' +
                   rule.selector +

test/index.test.js

@@ -1015,6 +1015,68 @@ const tests = [
     options: { mode: "pure" },
     expected: ":export { foo: __foo; }",
   },
+  {
+    name: "global selectors after an ignore comments should be pure",
+    options: { mode: "pure" },
+    input: `/* cssmodules-pure-ignore */
+            .global { a_value: some-value; }`,
+    expected: `/* cssmodules-pure-ignore */
+            .global { a_value: some-value; }`,
+  },
+  {
+    name: "global selectors after an ignore comments with postfix stays pure",
+    options: { mode: "pure" },
+    input: `/* cssmodules-pure-ignore With additional explanation */
+            .global { a_value: some-value; }`,
+    expected: `/* cssmodules-pure-ignore With additional explanation */
+            .global { a_value: some-value; }`,
+  },
+  {
+    name: "global selector after an ignore comments should still localize its properties",
+    options: { mode: "pure" },
+    input: `/* cssmodules-pure-ignore */
+            .global {
+                  animation: fadeOut;
+            }`,
+    expected: `/* cssmodules-pure-ignore */
+            .global {
+                  animation: :local(fadeOut);
+            }`,
+  },
+  {
+    name: "global selector after an ignore comments should still localize its child selectors",
+    options: { mode: "pure" },
+    input: `/* cssmodules-pure-ignore */
+            .outer {
+              .inner { a_value: some-value; }
+            }`,
+    expected: `/* cssmodules-pure-ignore */
+            .outer {
+              :local(.inner) { a_value: some-value; }
+            }`,
+  },
+  {
+    name: "global animation after an ignore comments should be pure",
+    options: { mode: "pure" },
+    input: `.foo { /* cssmodules-pure-ignore */
+             animation: fadeOut; }`,
+    expected: `:local(.foo) { /* cssmodules-pure-ignore */
+             animation: fadeOut; }`,
+  },
+  {
+    name: "global follow up properties after an ignore comments should be localized",
+    options: { mode: "pure" },
+    input: `.foo {
+             /* cssmodules-pure-ignore */
+             animation: fadeOut;
+             &:disabled { animation-name: localAnimation; }
+            }`,
+    expected: `:local(.foo) {
+             /* cssmodules-pure-ignore */
+             animation: fadeOut;
+             &:disabled { animation-name: :local(localAnimation); }
+            }`,
+  },
   {
     name: "handle negative animation-delay in animation shorthand",
     input: ".foo { animation: 1s -500ms; }",