Add tests for first class mixins (#1933)

js-api-spec/value/boolean.test.ts

@@ -30,6 +30,7 @@ describe('Sass boolean', () => {
       expect(value.assertFunction).toThrow();
       expect(value.assertMap).toThrow();
       expect(value.tryMap()).toBe(null);
+      expect(value.assertMixin).toThrow();
       expect(value.assertNumber).toThrow();
       expect(value.assertString).toThrow();
     });
@@ -60,6 +61,7 @@ describe('Sass boolean', () => {
       expect(value.assertFunction).toThrow();
       expect(value.assertMap).toThrow();
       expect(value.tryMap()).toBe(null);
+      expect(value.assertMixin).toThrow();
       expect(value.assertNumber).toThrow();
       expect(value.assertString).toThrow();
     });

js-api-spec/value/calculation.test.ts

@@ -48,6 +48,7 @@ describe('SassCalculation', () => {
       expect(() => calculation.assertFunction()).toThrow();
       expect(() => calculation.assertMap()).toThrow();
       expect(calculation.tryMap()).toBe(null);
+      expect(() => calculation.assertMixin()).toThrow();
       expect(() => calculation.assertNumber()).toThrow();
       expect(() => calculation.assertString()).toThrow();
     });

js-api-spec/value/color.test.ts

@@ -57,6 +57,7 @@ describe('SassColor', () => {
         expect(() => color.assertFunction()).toThrow();
         expect(() => color.assertMap()).toThrow();
         expect(color.tryMap()).toBe(null);
+        expect(() => color.assertMixin()).toThrow();
         expect(() => color.assertNumber()).toThrow();
         expect(() => color.assertString()).toThrow();
       });

js-api-spec/value/list.test.ts

@@ -30,6 +30,7 @@ describe('SassList', () => {
       expect(() => list.assertFunction()).toThrow();
       expect(() => list.assertMap()).toThrow();
       expect(list.tryMap()).toBe(null);
+      expect(() => list.assertMixin()).toThrow();
       expect(() => list.assertNumber()).toThrow();
       expect(() => list.assertString()).toThrow();
     });
@@ -358,6 +359,7 @@ describe('SassList', () => {
       expect(() => list.assertCalculation()).toThrow();
       expect(() => list.assertColor()).toThrow();
       expect(() => list.assertFunction()).toThrow();
+      expect(() => list.assertMixin()).toThrow();
       expect(() => list.assertNumber()).toThrow();
       expect(() => list.assertString()).toThrow();
     });

js-api-spec/value/map.test.ts

@@ -32,6 +32,7 @@ describe('SassMap', () => {
       expect(() => map.assertCalculation()).toThrow();
       expect(() => map.assertColor()).toThrow();
       expect(() => map.assertFunction()).toThrow();
+      expect(() => map.assertMixin()).toThrow();
       expect(() => map.assertNumber()).toThrow();
       expect(() => map.assertString()).toThrow();
     });

js-api-spec/value/mixin.test.ts

@@ -0,0 +1,46 @@
+// Copyright 2021 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 {SassMixin, compileString} from 'sass';
+
+import {spy} from '../utils';
+
+it('can round-trip a mixin reference from Sass', () => {
+  const fn = spy(args => {
+    expect(args).toBeArrayOfSize(1);
+    const value = args[0];
+    expect(value).toBeInstanceOf(SassMixin);
+    expect(value.assertCalculation).toThrow();
+    expect(value.assertColor).toThrow();
+    expect(value.assertFunction).toThrow();
+    expect(value.assertMap).toThrow();
+    expect(value.tryMap()).toBe(null);
+    expect(value.assertMixin()).toBe(value);
+    expect(value.assertNumber).toThrow();
+    expect(value.assertString).toThrow();
+
+    return value;
+  });
+
+  expect(
+    compileString(
+      `
+      @use 'sass:meta';
+
+      @mixin a() {
+        a {
+          b: c;
+        }
+      }
+
+      @include meta.apply(foo(meta.get-mixin('a')));
+    `,
+      {
+        functions: {'foo($arg)': fn},
+      }
+    ).css
+  ).toBe('a {\n  b: c;\n}');
+
+  expect(fn).toHaveBeenCalled();
+});

js-api-spec/value/null.test.ts

@@ -30,6 +30,7 @@ describe('Sass null', () => {
     expect(value.assertFunction).toThrow();
     expect(value.assertMap).toThrow();
     expect(value.tryMap()).toBe(null);
+    expect(value.assertMixin).toThrow();
     expect(value.assertNumber).toThrow();
     expect(value.assertString).toThrow();
   });

js-api-spec/value/number.test.ts

@@ -42,6 +42,7 @@ describe('Sass number', () => {
           expect(() => number.assertFunction()).toThrow();
           expect(() => number.assertMap()).toThrow();
           expect(number.tryMap()).toBe(null);
+          expect(() => number.assertMixin()).toThrow();
           expect(() => number.assertString()).toThrow();
         });
       });

js-api-spec/value/string.test.ts

@@ -59,6 +59,7 @@ describe('Sass string', () => {
       expect(value.assertFunction).toThrow();
       expect(value.assertMap).toThrow();
       expect(value.tryMap()).toBe(null);
+      expect(value.assertMixin).toThrow();
       expect(value.assertNumber).toThrow();
     });
   });

spec/core_functions/meta/accepts_content.hrx

@@ -0,0 +1,138 @@
+<===> options.yml
+---
+:todo:
+- sass/libsass#2807
+
+<===>
+================================================================================
+<===> accepts/direct_child/input.scss
+@use "sass:meta";
+
+@mixin a() {@content}
+
+a {b: meta.accepts-content(meta.get-mixin("a"))}
+
+<===> accepts/direct_child/output.css
+a {
+  b: true;
+}
+
+<===>
+================================================================================
+<===> accepts/nested_child/input.scss
+@use "sass:meta";
+
+@mixin a() {
+  @if false {@content}
+}
+
+a {b: meta.accepts-content(meta.get-mixin("a"))}
+
+<===> accepts/nested_child/output.css
+a {
+  b: true;
+}
+
+<===>
+================================================================================
+<===> accepts/builtin/input.scss
+@use "sass:meta";
+
+a {b: meta.accepts-content(meta.get-mixin(apply, meta))}
+
+<===> accepts/builtin/output.css
+a {
+  b: true;
+}
+
+<===>
+================================================================================
+<===> doesnt_accept/empty/input.scss
+@use "sass:meta";
+@mixin a() {}
+
+a {b: meta.accepts-content(meta.get-mixin("a"))}
+
+<===> doesnt_accept/empty/output.css
+a {
+  b: false;
+}
+
+<===>
+================================================================================
+<===> doesnt_accept/builtin/input.scss
+@use "sass:meta";
+@mixin a() {}
+
+a {b: meta.accepts-content(meta.get-mixin(load-css, meta))}
+
+<===> doesnt_accept/builtin/output.css
+a {
+  b: false;
+}
+
+<===>
+================================================================================
+<===> args/keyword/input.scss
+@use "sass:meta";
+
+a {b: meta.accepts-content($mixin: meta.get-mixin(apply, meta))}
+
+<===> args/keyword/output.css
+a {
+  b: true;
+}
+
+<===>
+================================================================================
+<===> error/args/too_few/input.scss
+@use "sass:meta";
+
+a {b: meta.accepts-content()}
+
+<===> error/args/too_few/error
+Error: Missing argument $mixin.
+  ,--> input.scss
+3 | a {b: meta.accepts-content()}
+  |       ^^^^^^^^^^^^^^^^^^^^^^ invocation
+  '
+  ,--> sass:meta
+1 | @function accepts-content($mixin) {
+  |           ======================= declaration
+  '
+  input.scss 3:7  root stylesheet
+
+<===>
+================================================================================
+<===> error/args/too_many/input.scss
+@use "sass:meta";
+@mixin a() {}
+
+a {b: meta.accepts-content(a, a)}
+
+<===> error/args/too_many/error
+Error: Only 1 argument allowed, but 2 were passed.
+  ,--> input.scss
+4 | a {b: meta.accepts-content(a, a)}
+  |       ^^^^^^^^^^^^^^^^^^^^^^^^^^ invocation
+  '
+  ,--> sass:meta
+1 | @function accepts-content($mixin) {
+  |           ======================= declaration
+  '
+  input.scss 4:7  root stylesheet
+
+<===>
+================================================================================
+<===> error/args/wrong_type/input.scss
+@use "sass:meta";
+
+a {b: meta.accepts-content(meta.get-function("red"))}
+
+<===> error/args/wrong_type/error
+Error: $mixin: get-function("red") is not a mixin reference.
+  ,
+3 | a {b: meta.accepts-content(meta.get-function("red"))}
+  |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  '
+  input.scss 3:7  root stylesheet