refactor(compiler-cli): cleanup inferences (#49863)

With the ts compiler updates these inferences have been fixed.

PR Close #49863

packages/compiler-cli/src/ngtsc/annotations/common/src/di.ts

@@ -143,9 +143,8 @@ export function validateConstructorDependencies(
   } else if (deps.deps !== null) {
     return deps.deps;
   } else {
-    // TODO(alxhub): this cast is necessary because the g3 typescript version doesn't narrow here.
     // There is at least one error.
-    const error = (deps as {errors: ConstructorDepError[]}).errors[0];
+    const error = deps.errors[0];
     throw createUnsuitableInjectionTokenError(clazz, error);
   }
 }

packages/compiler-cli/src/ngtsc/annotations/component/src/resources.ts

@@ -111,15 +111,7 @@ export type TemplateDeclaration = InlineTemplateDeclaration|ExternalTemplateDecl
 
 /** Determines the node to use for debugging purposes for the given TemplateDeclaration. */
 export function getTemplateDeclarationNodeForError(declaration: TemplateDeclaration): ts.Node {
-  // TODO(zarend): Change this to if/else when that is compatible with g3. This uses a switch
-  // because if/else fails to compile on g3. That is because g3 compiles this in non-strict mode
-  // where type inference does not work correctly.
-  switch (declaration.isInline) {
-    case true:
-      return declaration.expression;
-    case false:
-      return declaration.templateUrlExpression;
-  }
+  return declaration.isInline ? declaration.expression : declaration.templateUrlExpression;
 }
 
 export interface ExtractTemplateOptions {
@@ -199,9 +191,7 @@ export function extractTemplate(
       sourceMapping: {
         type: 'external',
         componentClass: node,
-        // TODO(alxhub): TS in g3 is unable to make this inference on its own, so cast it here
-        // until g3 is able to figure this out.
-        node: (template as ExternalTemplateDeclaration).templateUrlExpression,
+        node: template.templateUrlExpression,
         template: templateContent,
         templateUrl: template.resolvedTemplateUrl,
       },

packages/compiler-cli/src/ngtsc/typecheck/diagnostics/src/diagnostic.ts

@@ -61,10 +61,9 @@ export function makeTemplateDiagnostic(
     // For external temoplates, the HTML filename is used.
     const componentSf = mapping.componentClass.getSourceFile();
     const componentName = mapping.componentClass.name.text;
-    // TODO(alxhub): remove cast when TS in g3 supports this narrowing.
     const fileName = mapping.type === 'indirect' ?
         `${componentSf.fileName} (${componentName} template)` :
-        (mapping as ExternalTemplateSourceMapping).templateUrl;
+        mapping.templateUrl;
 
     let relatedInformation: ts.DiagnosticRelatedInformation[] = [];
     if (relatedMessages !== undefined) {