build: enable strict property initialization for entire repo

crisbeto · crisbeto · commit b3e1139140f3 · 2025-12-18T10:08:51.000+02:00
Enables strict property initialization for the whole repo and fixes a few failures that weren't caught earlier.
diff --git a/docs/src/assets/stackblitz/tsconfig.json b/docs/src/assets/stackblitz/tsconfig.json
@@ -19,6 +19,7 @@
     "noUnusedLocals": false,
     "useDefineForClassFields": false,
     "strictNullChecks": true,
+    "strictPropertyInitialization": true,
     "noImplicitReturns": true,
     "strictFunctionTypes": true,
     "noImplicitOverride": true,
diff --git a/src/aria/tree/tree-item.ts b/src/aria/tree/tree-item.ts
@@ -119,7 +119,7 @@ export class TreeItem<V> extends DeferredContentAware implements OnInit, OnDestr
   );
 
   /** The UI pattern for this item. */
-  _pattern: TreeItemPattern<V>;
+  _pattern!: TreeItemPattern<V>;
 
   constructor() {
     super();
diff --git a/src/bazel-tsconfig-build.json b/src/bazel-tsconfig-build.json
@@ -11,6 +11,7 @@
     "noUnusedParameters": false,
     "noUnusedLocals": false,
     "strictNullChecks": true,
+    "strictPropertyInitialization": true,
     "noPropertyAccessFromIndexSignature": true,
     "noImplicitReturns": true,
     "strictFunctionTypes": true,
diff --git a/src/cdk-experimental/tsconfig.json b/src/cdk-experimental/tsconfig.json
@@ -4,7 +4,6 @@
   "compilerOptions": {
     "rootDir": "..",
     "baseUrl": ".",
-    "strictPropertyInitialization": true,
     "paths": {
       "@angular/cdk/*": ["../cdk/*"],
       "@angular/cdk-experimental/*": ["../cdk-experimental/*"]
diff --git a/src/cdk/schematics/tsconfig.json b/src/cdk/schematics/tsconfig.json
@@ -6,6 +6,7 @@
     "moduleResolution": "node",
     "rootDir": ".",
     "strictNullChecks": true,
+    "strictPropertyInitialization": true,
     "noPropertyAccessFromIndexSignature": true,
     "strict": true,
     "useUnknownInCatchVariables": true,
diff --git a/src/cdk/testing/tests/test-sub-component.ts b/src/cdk/testing/tests/test-sub-component.ts
@@ -21,6 +21,6 @@ import {ChangeDetectionStrategy, Component, Input, ViewEncapsulation} from '@ang
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class TestSubComponent {
-  @Input() title: string;
-  @Input() items: string[];
+  @Input() title = '';
+  @Input() items: string[] = [];
 }
diff --git a/src/cdk/tsconfig.json b/src/cdk/tsconfig.json
@@ -4,7 +4,6 @@
   "compilerOptions": {
     "rootDir": "..",
     "baseUrl": ".",
-    "strictPropertyInitialization": true,
     "paths": {
       "@angular/cdk/*": ["./*"]
     }
diff --git a/src/components-examples/tsconfig.json b/src/components-examples/tsconfig.json
@@ -4,7 +4,6 @@
   "compilerOptions": {
     "rootDir": "..",
     "baseUrl": ".",
-    "strictPropertyInitialization": true,
     "paths": {
       "@angular/aria/*": ["../aria/*"],
       "@angular/cdk/*": ["../cdk/*"],
diff --git a/src/dev-app/tsconfig.json b/src/dev-app/tsconfig.json
@@ -5,7 +5,6 @@
     // Needed for Moment.js since it doesn't have a default export.
     "rootDir": "..",
     "baseUrl": ".",
-    "strictPropertyInitialization": true,
     "paths": {
       "@angular/aria": ["../aria"],
       "@angular/aria/*": ["../aria/*"],
diff --git a/src/google-maps/tsconfig.json b/src/google-maps/tsconfig.json
@@ -5,8 +5,7 @@
     "rootDir": "..",
     "baseUrl": ".",
     "paths": {},
-    "types": ["jasmine", "google.maps"],
-    "strictPropertyInitialization": true
+    "types": ["jasmine", "google.maps"]
   },
   "include": ["./**/*.ts", "../dev-mode-types.d.ts"]
 }
diff --git a/src/material-experimental/tsconfig.json b/src/material-experimental/tsconfig.json
@@ -4,7 +4,6 @@
   "compilerOptions": {
     "rootDir": "..",
     "baseUrl": ".",
-    "strictPropertyInitialization": true,
     "paths": {
       "@angular/cdk/*": ["../cdk/*"],
       "@angular/material/*": ["../material/*"],
diff --git a/src/material-moment-adapter/tsconfig.json b/src/material-moment-adapter/tsconfig.json
@@ -4,7 +4,6 @@
   "compilerOptions": {
     "rootDir": "..",
     "baseUrl": ".",
-    "strictPropertyInitialization": true,
     "paths": {
       "@angular/cdk/*": ["../cdk/*"],
       "@angular/material/*": ["../material/*"],
diff --git a/src/material/timepicker/timepicker.ts b/src/material/timepicker/timepicker.ts
@@ -143,7 +143,7 @@ export class MatTimepicker<D> implements OnDestroy, MatOptionParentComponent {
   private _overlayRef: OverlayRef | null = null;
   private _portal: TemplatePortal<unknown> | null = null;
   private _optionsCacheKey: string | null = null;
-  private _localeChanges: Subscription;
+  private _localeChanges: Subscription | undefined;
   private _onOpenRender: AfterRenderRef | null = null;
 
   protected _panelTemplate = viewChild.required<TemplateRef<unknown>>('panelTemplate');
@@ -307,7 +307,7 @@ export class MatTimepicker<D> implements OnDestroy, MatOptionParentComponent {
 
   ngOnDestroy(): void {
     this._keyManager.destroy();
-    this._localeChanges.unsubscribe();
+    this._localeChanges?.unsubscribe();
     this._onOpenRender?.destroy();
     this._overlayRef?.dispose();
   }
diff --git a/src/material/tsconfig.json b/src/material/tsconfig.json
@@ -4,7 +4,6 @@
   "compilerOptions": {
     "rootDirs": ["..", "../../tools"],
     "baseUrl": ".",
-    "strictPropertyInitialization": true,
     "paths": {
       "@angular/cdk": ["../cdk"],
       "@angular/cdk/*": ["../cdk/*"],
diff --git a/src/youtube-player/tsconfig.json b/src/youtube-player/tsconfig.json
@@ -5,8 +5,7 @@
     "rootDir": "..",
     "baseUrl": ".",
     "paths": {},
-    "types": ["jasmine"],
-    "strictPropertyInitialization": true
+    "types": ["jasmine"]
   },
   "include": ["*.ts", "../dev-mode-types.d.ts"]
 }
diff --git a/tsconfig.json b/tsconfig.json
@@ -11,6 +11,7 @@
     "noFallthroughCasesInSwitch": true,
     "noUnusedLocals": false,
     "strictNullChecks": true,
+    "strictPropertyInitialization": true,
     "noPropertyAccessFromIndexSignature": true,
     "useUnknownInCatchVariables": true,
     "noImplicitOverride": true,

Original file line number	Diff line number	Diff line change
`@@ -21,6 +21,6 @@ import {ChangeDetectionStrategy, Component, Input, ViewEncapsulation} from '@ang`
`21`	`21`	`changeDetection: ChangeDetectionStrategy.OnPush,`
`22`	`22`	`})`
`23`	`23`	`export class TestSubComponent {`
`24`		`- @Input() title: string;`
`25`		`- @Input() items: string[];`
	`24`	`+ @Input() title = '';`
	`25`	`+ @Input() items: string[] = [];`
`26`	`26`	`}`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,6 @@`
`4`	`4`	`"compilerOptions": {`
`5`	`5`	`"rootDir": "..",`
`6`	`6`	`"baseUrl": ".",`
`7`		`- "strictPropertyInitialization": true,`
`8`	`7`	`"paths": {`
`9`	`8`	`"@angular/cdk/": ["./"]`
`10`	`9`	`}`