tests: introduce randomness in mocks

src/tests/utils/mocks/MockKwinClient.ts

@@ -90,28 +90,46 @@ class MockKwinClient {
 
     public set fullScreen(fullScreen: boolean) {
         const oldFullScreen = this._fullScreen;
-
         this.hasBorder = !fullScreen;
 
-        this._fullScreen = fullScreen;
-        this.fullScreenChanged.fire();
-
-        if (oldFullScreen && !fullScreen) {
-            // when switching from full-screen to windowed, Kwin sometimes first adds the frame before changing the frameGeometry to the final value
-            this.frameGeometry = new MockQmlRect(
-                -MockKwinClient.borderThickness,
-                -MockKwinClient.borderThickness,
-                screenWidth + 2 * MockKwinClient.borderThickness,
-                screenHeight + 2 * MockKwinClient.borderThickness,
-            );
-        }
-
-        this.windowed = !fullScreen;
-        if (fullScreen) {
-            this.frameGeometry = new MockQmlRect(0, 0, screenWidth, screenHeight);
-        } else {
-            this.frameGeometry = this.windowedFrameGeometry;
-        }
+        runReorder(
+            () => {
+                this._fullScreen = fullScreen;
+                this.fullScreenChanged.fire();
+            },
+            () => {
+                if (oldFullScreen && !fullScreen) {
+                    // when switching from full-screen to windowed, Kwin sometimes first adds the frame before changing the frameGeometry to the final value
+                    runOneOf(
+                        () => {
+                            this.frameGeometry = new MockQmlRect(
+                                0,
+                                0,
+                                screenWidth + 2 * MockKwinClient.borderThickness,
+                                screenHeight + 2 * MockKwinClient.borderThickness,
+                            );
+                        },
+                        () => {
+                            this.frameGeometry = new MockQmlRect(
+                                -MockKwinClient.borderThickness,
+                                -MockKwinClient.borderThickness,
+                                screenWidth + 2 * MockKwinClient.borderThickness,
+                                screenHeight + 2 * MockKwinClient.borderThickness,
+                            );
+                        },
+                        () => {},
+                    );
+                }
+            },
+            () => {
+                this.windowed = !fullScreen;
+                if (fullScreen) {
+                    this.frameGeometry = new MockQmlRect(0, 0, screenWidth, screenHeight);
+                } else {
+                    this.frameGeometry = this.windowedFrameGeometry;
+                }
+            },
+        );
     }
 
     public get frameGeometry() {

src/tests/utils/random.ts

@@ -0,0 +1,26 @@
+function runOneOf(...fs: (() => void)[]) {
+    randomItem(fs)();
+}
+
+function runReorder(...fs: (() => void)[]) {
+    shuffle(fs);
+    for (const f of fs) {
+        f();
+    }
+}
+
+function randomInt(n: number) {
+    return Math.floor(Math.random() * n);
+}
+
+function randomItem<T>(items: T[]): T {
+    return items[randomInt(items.length)];
+}
+
+function shuffle(items: any[]) {
+    for (let n = items.length; n > 1; n--) {
+        const i = n-1;
+        const j = randomInt(n);
+        [items[i], items[j]] = [items[j], items[i]];
+    }
+}