[BUGFIX] Add assertion for invalid component helper argument

packages/@ember/-internals/glimmer/tests/integration/components/dynamic-components-test.js

@@ -1,5 +1,5 @@
 import { DEBUG } from '@glimmer/env';
-import { moduleFor, RenderingTestCase, strip, runTask } from 'internal-test-helpers';
+import { moduleFor, RenderingTestCase, strip, runTask, runAppend } from 'internal-test-helpers';
 
 import { set, computed } from '@ember/object';
 import { precompileTemplate } from '@ember/template-compilation';
@@ -87,6 +87,50 @@ moduleFor(
       });
     }
 
+    ['@test it throws a useful assertion for an invalid dynamic component value in non-strict mode'](
+      assert
+    ) {
+      if (!DEBUG) {
+        assert.expect(0);
+        return;
+      }
+
+      assert.throws(() => {
+        this.render('{{component this.componentName}}', {
+          componentName: { name: 'not-a-component' },
+        });
+      }, /The `{{component}}` helper received an invalid value\. It expects a component definition or a string component name\./);
+    }
+
+    ['@test it throws a useful assertion for an invalid dynamic component value in strict mode'](
+      assert
+    ) {
+      if (!DEBUG) {
+        assert.expect(0);
+        return;
+      }
+
+      assert.throws(() => {
+        this.owner.register(
+          'template:-top-level',
+          this.compile('{{component this.componentName}}', {
+            moduleName: '-top-level',
+            strictMode: true,
+          })
+        );
+
+        let attrs = {
+          componentName: { name: 'not-a-component' },
+          tagName: '',
+          layoutName: '-top-level',
+        };
+
+        this.owner.register('component:-top-level', Component.extend(attrs));
+        this.component = this.owner.lookup('component:-top-level');
+        runAppend(this.component);
+      }, /The `{{component}}` helper received an invalid value\. In strict mode, it expects a component definition\./);
+    }
+
     ['@test it has an element']() {
       let instance;
 

packages/@glimmer/runtime/lib/compiled/opcodes/component.ts

@@ -72,6 +72,7 @@ import { expect, unwrap } from '@glimmer/debug-util/lib/platform-utils';
 import assert from '@glimmer/debug-util/lib/assert';
 import { unwrapTemplate } from '@glimmer/debug-util/lib/template';
 import { registerDestructor } from '@glimmer/destroyable';
+import { hasInternalComponentManager } from '@glimmer/manager/lib/internal/api';
 import { managerHasCapability } from '@glimmer/manager/lib/util/capabilities';
 import { isConstRef, valueForRef } from '@glimmer/reference/lib/reference';
 import { assign } from '@glimmer/util/lib/object-utils';
@@ -168,6 +169,20 @@ APPEND_OPCODES.add(VM_RESOLVE_DYNAMIC_COMPONENT_OP, (vm, { op1: _isStrict }) =>
 
   vm.loadValue($t1, null); // Clear the temp register
 
+  if (DEBUG) {
+    assert(
+      component === null ||
+        component === undefined ||
+        typeof component === 'string' ||
+        isCurriedValue(component) ||
+        ((typeof component === 'object' || typeof component === 'function') &&
+          hasInternalComponentManager(component)),
+      isStrict
+        ? 'The `{{component}}` helper received an invalid value. In strict mode, it expects a component definition.'
+        : 'The `{{component}}` helper received an invalid value. It expects a component definition or a string component name.'
+    );
+  }
+
   let definition: ComponentDefinition | CurriedValue;
 
   if (typeof component === 'string') {