Revert "Remove deprecated disabledWhen"

packages/@ember/-internals/glimmer/lib/components/-link-to.ts

@@ -879,6 +879,12 @@ const LinkComponent = EmberComponent.extend({
   loadingHref: '#',
 
   didReceiveAttrs() {
+    let { disabledWhen } = this;
+
+    if (disabledWhen !== undefined) {
+      this.set('disabled', disabledWhen);
+    }
+
     let { params } = this;
 
     if (!params || params.length === 0) {

packages/@ember/-internals/glimmer/lib/components/link-to.ts

@@ -614,6 +614,70 @@ if (EMBER_MODERNIZED_BUILT_IN_COMPONENTS) {
     });
   }
 
+  // @disabledWhen
+  {
+    let superIsSupportedArgument = prototype['isSupportedArgument'];
+
+    Object.defineProperty(prototype, 'isSupportedArgument', {
+      configurable: true,
+      enumerable: false,
+      value: function isSupportedArgument(this: LinkTo, name: string): boolean {
+        if (this.modernized) {
+          if (name === 'disabledWhen') {
+            deprecate(
+              'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. ' +
+                'Use the `@disabled` argument instead.',
+              false,
+              {
+                id: 'ember.link-to.disabled-when',
+                for: 'ember-source',
+                since: {},
+                until: '4.0.0',
+              }
+            );
+
+            return true;
+          }
+        }
+
+        return superIsSupportedArgument.call(this, name);
+      },
+    });
+
+    let superDescriptor = descriptorFor(prototype, 'isDisabled');
+
+    assert(
+      `[BUG] expecting isDisabled to be a getter on <LinkTo>`,
+      superDescriptor && typeof superDescriptor.get === 'function'
+    );
+
+    let superGetter = superDescriptor.get as (this: LinkTo) => boolean;
+
+    Object.defineProperty(prototype, 'isDisabled', {
+      configurable: true,
+      enumerable: false,
+      get: function isDisabled(this: LinkTo): boolean {
+        if ('disabledWhen' in this.args.named) {
+          deprecate(
+            'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. ' +
+              'Use the `@disabled` argument instead.',
+            false,
+            {
+              id: 'ember.link-to.disabled-when',
+              for: 'ember-source',
+              since: {},
+              until: '4.0.0',
+            }
+          );
+
+          return Boolean(this.named('disabledWhen'));
+        }
+
+        return superGetter.call(this);
+      },
+    });
+  }
+
   // QP
   {
     let superModelsDescriptor = descriptorFor(prototype, 'models');

packages/@ember/-internals/glimmer/tests/integration/components/link-to/routing-angle-test.js

@@ -147,6 +147,64 @@ moduleFor(
       assert.strictEqual(this.$('#about-link').attr('href'), null, 'there is no href attribute');
     }
 
+    async [`@test [DEPRECATED] it applies a 'disabled' class when disabledWhen`](assert) {
+      this.addTemplate(
+        'index',
+        `
+        <LinkTo id="about-link-static" @route="about" @disabledWhen="truthy">About</LinkTo>
+        <LinkTo id="about-link-dynamic" @route="about" @disabledWhen={{this.dynamicDisabledWhen}}>About</LinkTo>
+        `
+      );
+
+      let controller;
+
+      this.add(
+        'controller:index',
+        class extends Controller {
+          constructor(...args) {
+            super(...args);
+            controller = this;
+          }
+
+          dynamicDisabledWhen = true;
+        }
+      );
+
+      await expectDeprecationAsync(
+        () => this.visit('/'),
+        'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. Use the `@disabled` argument instead.',
+        EMBER_MODERNIZED_BUILT_IN_COMPONENTS
+      );
+
+      assert.equal(
+        this.$('#about-link-static.disabled').length,
+        1,
+        'The static link is disabled when its disabledWhen is true'
+      );
+      assert.equal(
+        this.$('#about-link-dynamic.disabled').length,
+        1,
+        'The dynamic link is disabled when its disabledWhen is true'
+      );
+
+      expectDeprecation(
+        () => runTask(() => controller.set('dynamicDisabledWhen', false)),
+        'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. Use the `@disabled` argument instead.',
+        EMBER_MODERNIZED_BUILT_IN_COMPONENTS
+      );
+
+      assert.equal(
+        this.$('#about-link-static.disabled').length,
+        1,
+        'The static link is disabled when its disabledWhen is true'
+      );
+      assert.strictEqual(
+        this.$('#about-link-dynamic.disabled').length,
+        0,
+        'The dynamic link is re-enabled when its disabledWhen becomes false'
+      );
+    }
+
     async [`@test it applies a 'disabled' class when disabled`](assert) {
       this.addTemplate(
         'index',
@@ -326,6 +384,27 @@ moduleFor(
       );
     }
 
+    async [`@test [DEPRECATED] it does not respond to clicks when disabledWhen`](assert) {
+      this.addTemplate(
+        'index',
+        `<LinkTo id="about-link" @route="about" @disabledWhen={{true}}>About</LinkTo>`
+      );
+
+      await expectDeprecationAsync(
+        () => this.visit('/'),
+        'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. Use the `@disabled` argument instead.',
+        EMBER_MODERNIZED_BUILT_IN_COMPONENTS
+      );
+
+      await expectDeprecationAsync(
+        () => this.click('#about-link'),
+        'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. Use the `@disabled` argument instead.',
+        EMBER_MODERNIZED_BUILT_IN_COMPONENTS
+      );
+
+      assert.strictEqual(this.$('h3.about').length, 0, 'Transitioning did not occur');
+    }
+
     async [`@test it does not respond to clicks when disabled`](assert) {
       this.addTemplate(
         'index',
@@ -372,7 +451,7 @@ moduleFor(
       assert.equal(
         this.$('h3.about').length,
         1,
-        'Transitioning did occur when disabled became false'
+        'Transitioning did occur when disabledWhen became false'
       );
     }
 

packages/@ember/-internals/glimmer/tests/integration/components/link-to/routing-curly-test.js

@@ -152,6 +152,64 @@ moduleFor(
       );
     }
 
+    async [`@test [DEPRECATED] it applies a 'disabled' class when disabledWhen`](assert) {
+      this.addTemplate(
+        'index',
+        `
+        <div id="about-link-static">{{#link-to route="about" disabledWhen="truthy"}}About{{/link-to}}</div>
+        <div id="about-link-dynamic">{{#link-to route="about" disabledWhen=this.dynamicDisabledWhen}}About{{/link-to}}</div>
+        `
+      );
+
+      let controller;
+
+      this.add(
+        'controller:index',
+        class extends Controller {
+          constructor(...args) {
+            super(...args);
+            controller = this;
+          }
+
+          dynamicDisabledWhen = true;
+        }
+      );
+
+      await expectDeprecationAsync(
+        () => this.visit('/'),
+        'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. Use the `@disabled` argument instead.',
+        EMBER_MODERNIZED_BUILT_IN_COMPONENTS
+      );
+
+      assert.equal(
+        this.$('#about-link-static > a.disabled').length,
+        1,
+        'The static link is disabled when its disabledWhen is true'
+      );
+      assert.equal(
+        this.$('#about-link-dynamic > a.disabled').length,
+        1,
+        'The dynamic link is disabled when its disabledWhen is true'
+      );
+
+      expectDeprecation(
+        () => runTask(() => controller.set('dynamicDisabledWhen', false)),
+        'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. Use the `@disabled` argument instead.',
+        EMBER_MODERNIZED_BUILT_IN_COMPONENTS
+      );
+
+      assert.equal(
+        this.$('#about-link-static > a.disabled').length,
+        1,
+        'The static link is disabled when its disabledWhen is true'
+      );
+      assert.strictEqual(
+        this.$('#about-link-dynamic > a.disabled').length,
+        0,
+        'The dynamic link is re-enabled when its disabledWhen becomes false'
+      );
+    }
+
     async [`@test it applies a 'disabled' class when disabled`](assert) {
       this.addTemplate(
         'index',
@@ -193,7 +251,7 @@ moduleFor(
       assert.equal(
         this.$('#about-link-static > a.disabled').length,
         1,
-        'The static link is disabled when its disabled is true'
+        'The static link is disabled when its disabledWhen is true'
       );
       assert.strictEqual(
         this.$('#about-link-dynamic > a.disabled').length,
@@ -338,6 +396,27 @@ moduleFor(
       );
     }
 
+    async [`@test [DEPRECATED] it does not respond to clicks when disabledWhen`](assert) {
+      this.addTemplate(
+        'index',
+        `<div id="about-link">{{#link-to route="about" disabledWhen=true}}About{{/link-to}}</div>`
+      );
+
+      await expectDeprecationAsync(
+        () => this.visit('/'),
+        'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. Use the `@disabled` argument instead.',
+        EMBER_MODERNIZED_BUILT_IN_COMPONENTS
+      );
+
+      await expectDeprecationAsync(
+        () => this.click('#about-link > a'),
+        'Passing the `@disabledWhen` argument to <LinkTo> is deprecated. Use the `@disabled` argument instead.',
+        EMBER_MODERNIZED_BUILT_IN_COMPONENTS
+      );
+
+      assert.strictEqual(this.$('h3.about').length, 0, 'Transitioning did not occur');
+    }
+
     async [`@test it does not respond to clicks when disabled`](assert) {
       this.addTemplate(
         'index',
@@ -384,7 +463,7 @@ moduleFor(
       assert.equal(
         this.$('h3.about').length,
         1,
-        'Transitioning did occur when disabled became false'
+        'Transitioning did occur when disabledWhen became false'
       );
     }