Add sass-parser support for the @warn rule

pkg/sass-parser/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 * Add support for parsing variable declarations.
 
+* Add support for parsing the `@warn` rule.
+
 ## 0.4.1
 
 * Add `BooleanExpression` and `NumberExpression`.

pkg/sass-parser/lib/index.ts

@@ -101,6 +101,7 @@ export {
   VariableDeclarationProps,
   VariableDeclarationRaws,
 } from './src/statement/variable-declaration';
+export {WarnRule, WarnRuleProps, WarnRuleRaws} from './src/statement/warn-rule';
 
 /** Options that can be passed to the Sass parsers to control their behavior. */
 export type SassParserOptions = Pick<postcss.ProcessOptions, 'from' | 'map'>;

pkg/sass-parser/lib/src/sass-internal.ts

@@ -188,6 +188,10 @@ declare namespace SassInternal {
     readonly isGlobal: boolean;
   }
 
+  class WarnRule extends Statement {
+    readonly expression: Expression;
+  }
+
   class ConfiguredVariable extends SassNode {
     readonly name: string;
     readonly expression: Expression;
@@ -247,6 +251,7 @@ export type StyleRule = SassInternal.StyleRule;
 export type SupportsRule = SassInternal.SupportsRule;
 export type UseRule = SassInternal.UseRule;
 export type VariableDeclaration = SassInternal.VariableDeclaration;
+export type WarnRule = SassInternal.WarnRule;
 export type ConfiguredVariable = SassInternal.ConfiguredVariable;
 export type Interpolation = SassInternal.Interpolation;
 export type Expression = SassInternal.Expression;
@@ -270,6 +275,7 @@ export interface StatementVisitorObject<T> {
   visitSupportsRule(node: SupportsRule): T;
   visitUseRule(node: UseRule): T;
   visitVariableDeclaration(node: VariableDeclaration): T;
+  visitWarnRule(node: WarnRule): T;
 }
 
 export interface ExpressionVisitorObject<T> {

pkg/sass-parser/lib/src/statement/__snapshots__/warn-rule.test.ts.snap

@@ -0,0 +1,20 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`a @warn rule toJSON 1`] = `
+{
+  "inputs": [
+    {
+      "css": "@warn foo",
+      "hasBOM": false,
+      "id": "<input css _____>",
+    },
+  ],
+  "name": "warn",
+  "params": "foo",
+  "raws": {},
+  "sassType": "warn-rule",
+  "source": <1:1-1:10 in 0>,
+  "type": "atrule",
+  "warnExpression": <foo>,
+}
+`;

pkg/sass-parser/lib/src/statement/index.ts

@@ -22,6 +22,7 @@ import {
   VariableDeclaration,
   VariableDeclarationProps,
 } from './variable-declaration';
+import {WarnRule, WarnRuleProps} from './warn-rule';
 
 // TODO: Replace this with the corresponding Sass types once they're
 // implemented.
@@ -54,7 +55,8 @@ export type StatementType =
   | 'error-rule'
   | 'use-rule'
   | 'sass-comment'
-  | 'variable-declaration';
+  | 'variable-declaration'
+  | 'warn-rule';
 
 /**
  * All Sass statements that are also at-rules.
@@ -67,7 +69,8 @@ export type AtRule =
   | ErrorRule
   | ForRule
   | GenericAtRule
-  | UseRule;
+  | UseRule
+  | WarnRule;
 
 /**
  * All Sass statements that are comments.
@@ -103,7 +106,8 @@ export type ChildProps =
   | RuleProps
   | SassCommentChildProps
   | UseRuleProps
-  | VariableDeclarationProps;
+  | VariableDeclarationProps
+  | WarnRuleProps;
 
 /**
  * The Sass eqivalent of PostCSS's `ContainerProps`.
@@ -192,6 +196,7 @@ const visitor = sassInternal.createStatementVisitor<Statement>({
   },
   visitUseRule: inner => new UseRule(undefined, inner),
   visitVariableDeclaration: inner => new VariableDeclaration(undefined, inner),
+  visitWarnRule: inner => new WarnRule(undefined, inner),
 });
 
 /** Appends parsed versions of `internal`'s children to `container`. */
@@ -310,6 +315,8 @@ export function normalize(
       result.push(new UseRule(node));
     } else if ('variableName' in node) {
       result.push(new VariableDeclaration(node));
+    } else if ('warnExpression' in node) {
+      result.push(new WarnRule(node));
     } else {
       result.push(...postcssNormalizeAndConvertToSass(self, node, sample));
     }

pkg/sass-parser/lib/src/statement/warn-rule.test.ts

@@ -0,0 +1,205 @@
+// Copyright 2024 Google Inc. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+import {StringExpression, WarnRule, sass, scss} from '../..';
+import * as utils from '../../../test/utils';
+
+describe('a @warn rule', () => {
+  let node: WarnRule;
+  function describeNode(description: string, create: () => WarnRule): void {
+    describe(description, () => {
+      beforeEach(() => void (node = create()));
+
+      it('has a name', () => expect(node.name.toString()).toBe('warn'));
+
+      it('has an expression', () =>
+        expect(node).toHaveStringExpression('warnExpression', 'foo'));
+
+      it('has matching params', () => expect(node.params).toBe('foo'));
+
+      it('has undefined nodes', () => expect(node.nodes).toBeUndefined());
+    });
+  }
+
+  describeNode(
+    'parsed as SCSS',
+    () => scss.parse('@warn foo').nodes[0] as WarnRule
+  );
+
+  describeNode(
+    'parsed as Sass',
+    () => sass.parse('@warn foo').nodes[0] as WarnRule
+  );
+
+  describeNode(
+    'constructed manually',
+    () =>
+      new WarnRule({
+        warnExpression: {text: 'foo'},
+      })
+  );
+
+  describeNode('constructed from ChildProps', () =>
+    utils.fromChildProps({
+      warnExpression: {text: 'foo'},
+    })
+  );
+
+  it('throws an error when assigned a new name', () =>
+    expect(
+      () =>
+        (new WarnRule({
+          warnExpression: {text: 'foo'},
+        }).name = 'bar')
+    ).toThrow());
+
+  describe('assigned a new expression', () => {
+    beforeEach(() => {
+      node = scss.parse('@warn foo').nodes[0] as WarnRule;
+    });
+
+    it('sets an empty string expression as undefined params', () => {
+      node.params = undefined;
+      expect(node.params).toBe('');
+      expect(node).toHaveStringExpression('warnExpression', '');
+    });
+
+    it('sets an empty string expression as empty string params', () => {
+      node.params = '';
+      expect(node.params).toBe('');
+      expect(node).toHaveStringExpression('warnExpression', '');
+    });
+
+    it("removes the old expression's parent", () => {
+      const oldExpression = node.warnExpression;
+      node.warnExpression = {text: 'bar'};
+      expect(oldExpression.parent).toBeUndefined();
+    });
+
+    it("assigns the new expression's parent", () => {
+      const expression = new StringExpression({text: 'bar'});
+      node.warnExpression = expression;
+      expect(expression.parent).toBe(node);
+    });
+
+    it('assigns the expression explicitly', () => {
+      const expression = new StringExpression({text: 'bar'});
+      node.warnExpression = expression;
+      expect(node.warnExpression).toBe(expression);
+    });
+
+    it('assigns the expression as ExpressionProps', () => {
+      node.warnExpression = {text: 'bar'};
+      expect(node).toHaveStringExpression('warnExpression', 'bar');
+    });
+
+    it('assigns the expression as params', () => {
+      node.params = 'bar';
+      expect(node).toHaveStringExpression('warnExpression', 'bar');
+    });
+  });
+
+  describe('stringifies', () => {
+    describe('to SCSS', () => {
+      it('with default raws', () =>
+        expect(
+          new WarnRule({
+            warnExpression: {text: 'foo'},
+          }).toString()
+        ).toBe('@warn foo;'));
+
+      it('with afterName', () =>
+        expect(
+          new WarnRule({
+            warnExpression: {text: 'foo'},
+            raws: {afterName: '/**/'},
+          }).toString()
+        ).toBe('@warn/**/foo;'));
+
+      it('with between', () =>
+        expect(
+          new WarnRule({
+            warnExpression: {text: 'foo'},
+            raws: {between: '/**/'},
+          }).toString()
+        ).toBe('@warn foo/**/;'));
+    });
+  });
+
+  describe('clone', () => {
+    let original: WarnRule;
+    beforeEach(() => {
+      original = scss.parse('@warn foo').nodes[0] as WarnRule;
+      // TODO: remove this once raws are properly parsed
+      original.raws.between = '  ';
+    });
+
+    describe('with no overrides', () => {
+      let clone: WarnRule;
+      beforeEach(() => void (clone = original.clone()));
+
+      describe('has the same properties:', () => {
+        it('params', () => expect(clone.params).toBe('foo'));
+
+        it('warnExpression', () =>
+          expect(clone).toHaveStringExpression('warnExpression', 'foo'));
+
+        it('raws', () => expect(clone.raws).toEqual({between: '  '}));
+
+        it('source', () => expect(clone.source).toBe(original.source));
+      });
+
+      describe('creates a new', () => {
+        it('self', () => expect(clone).not.toBe(original));
+
+        for (const attr of ['warnExpression', 'raws'] as const) {
+          it(attr, () => expect(clone[attr]).not.toBe(original[attr]));
+        }
+      });
+    });
+
+    describe('overrides', () => {
+      describe('raws', () => {
+        it('defined', () =>
+          expect(original.clone({raws: {afterName: '  '}}).raws).toEqual({
+            afterName: '  ',
+          }));
+
+        it('undefined', () =>
+          expect(original.clone({raws: undefined}).raws).toEqual({
+            between: '  ',
+          }));
+      });
+
+      describe('warnExpression', () => {
+        describe('defined', () => {
+          let clone: WarnRule;
+          beforeEach(() => {
+            clone = original.clone({warnExpression: {text: 'bar'}});
+          });
+
+          it('changes params', () => expect(clone.params).toBe('bar'));
+
+          it('changes warnExpression', () =>
+            expect(clone).toHaveStringExpression('warnExpression', 'bar'));
+        });
+
+        describe('undefined', () => {
+          let clone: WarnRule;
+          beforeEach(() => {
+            clone = original.clone({warnExpression: undefined});
+          });
+
+          it('preserves params', () => expect(clone.params).toBe('foo'));
+
+          it('preserves warnExpression', () =>
+            expect(clone).toHaveStringExpression('warnExpression', 'foo'));
+        });
+      });
+    });
+  });
+
+  it('toJSON', () =>
+    expect(scss.parse('@warn foo').nodes[0]).toMatchSnapshot());
+});