[BUGFIX types] Add missing type declarations in the preview types for…

… @ember/template-compilation

type-tests/@ember/template-compilation.ts

@@ -0,0 +1,28 @@
+import { precompileTemplate } from '@ember/template-compilation';
+import { setComponentTemplate } from '@ember/component';
+import templateOnly from '@ember/component/template-only';
+
+import { expectTypeOf } from 'expect-type';
+
+// Valid usages
+precompileTemplate(`Hello World`, { moduleName: 'foo' });
+precompileTemplate(`Hello World`, { strictMode: true });
+precompileTemplate(`Hello World`, { strictMode: false });
+precompileTemplate(`Hello World`, { strictMode: true, scope: () => ({}) });
+precompileTemplate(`Hello World`, { strictMode: true, scope: () => ({ setComponentTemplate }) });
+precompileTemplate(`Hello World`, { strictMode: true, moduleName: 'hello', scope: () => ({}) });
+
+// Integration, since this is the primary use case for precompileTemplate
+expectTypeOf(setComponentTemplate(precompileTemplate(`Hello World`), templateOnly())).toBeObject();
+
+// @ts-expect-error scope must be a function
+precompileTemplate(`Hello World`, { strictMode: true, scope: {} });
+
+// @ts-expect-error scope must return an object
+precompileTemplate(`Hello World`, { strictMode: true, scope: () => {} });
+
+// @ts-expect-error scope must return an object and arrays are not the kind of object we want
+precompileTemplate(`Hello World`, { strictMode: true, scope: () => [] });
+
+// @ts-expect-error scope has no purpose when strictMode is false
+precompileTemplate(`Hello World`, { strictMode: false, scope: () => ({}) });

types/preview/@ember/template-compilation/index.d.ts

@@ -0,0 +1,26 @@
+/**
+ * References:
+ *  - https://github.com/emberjs/rfcs/pull/496
+ *  - https://github.com/emberjs/rfcs/pull/779
+ */
+declare module '@ember/template-compilation' {
+  interface TemplateFactory {
+    __htmlbars_inline_precompile_template_factory: any;
+  }
+
+  type PrecompileTemplateOptions =
+    | {
+        strictMode?: false;
+        moduleName?: string;
+      }
+    | {
+        strictMode: true;
+        moduleName?: string;
+        scope?: () => Record<string, unknown>;
+      };
+
+  export function precompileTemplate(
+    template: string,
+    options?: PrecompileTemplateOptions
+  ): TemplateFactory;
+}

types/preview/index.d.ts

@@ -117,6 +117,8 @@ import './@ember/string';
 import './@ember/template';
 import './@ember/template/-private/handlebars';
 
+import './@ember/template-compilation';
+
 import './@ember/test';
 import './@ember/test/adapter';