Fix decorations with height > 1

Fixes #4855

src/common/services/DecorationService.test.ts

@@ -9,12 +9,16 @@ import { IMarker } from 'common/Types';
 import { Disposable } from 'vs/base/common/lifecycle';
 import { Emitter } from 'vs/base/common/event';
 
-const fakeMarker: IMarker = Object.freeze(new class extends Disposable {
-  public readonly id = 1;
-  public readonly line = 1;
-  public readonly isDisposed = false;
-  public readonly onDispose = new Emitter<void>().event;
-}());
+function createFakeMarker(line: number): IMarker {
+  return Object.freeze(new class extends Disposable {
+    public readonly id = 1;
+    public readonly line = line;
+    public readonly isDisposed = false;
+    public readonly onDispose = new Emitter<void>().event;
+  }());
+}
+
+const fakeMarker: IMarker = createFakeMarker(1);
 
 describe('DecorationService', () => {
   it('should set isDisposed to true after dispose', () => {
@@ -27,4 +31,89 @@ describe('DecorationService', () => {
     decoration!.dispose();
     assert.isTrue(decoration!.isDisposed);
   });
+
+  describe('forEachDecorationAtCell', () => {
+    it('should find decoration at its marker line', () => {
+      const service = new DecorationService();
+      const decoration = service.registerDecoration({
+        marker: createFakeMarker(5),
+        width: 10
+      });
+      assert.ok(decoration);
+
+      const found: typeof decoration[] = [];
+      service.forEachDecorationAtCell(0, 5, undefined, d => found.push(d));
+      assert.strictEqual(found.length, 1);
+    });
+
+    it('should find decoration with height > 1 on subsequent lines', () => {
+      const service = new DecorationService();
+      const decoration = service.registerDecoration({
+        marker: createFakeMarker(5),
+        width: 10,
+        height: 3
+      });
+      assert.ok(decoration);
+
+      const foundAt5: typeof decoration[] = [];
+      service.forEachDecorationAtCell(0, 5, undefined, d => foundAt5.push(d));
+      assert.strictEqual(foundAt5.length, 1);
+
+      const foundAt6: typeof decoration[] = [];
+      service.forEachDecorationAtCell(0, 6, undefined, d => foundAt6.push(d));
+      assert.strictEqual(foundAt6.length, 1);
+
+      const foundAt7: typeof decoration[] = [];
+      service.forEachDecorationAtCell(0, 7, undefined, d => foundAt7.push(d));
+      assert.strictEqual(foundAt7.length, 1);
+
+      const foundAt8: typeof decoration[] = [];
+      service.forEachDecorationAtCell(0, 8, undefined, d => foundAt8.push(d));
+      assert.strictEqual(foundAt8.length, 0);
+    });
+
+    it('should not find decoration outside its x range', () => {
+      const service = new DecorationService();
+      const decoration = service.registerDecoration({
+        marker: createFakeMarker(5),
+        x: 5,
+        width: 3,
+        height: 2
+      });
+      assert.ok(decoration);
+
+      const foundAtX4: typeof decoration[] = [];
+      service.forEachDecorationAtCell(4, 5, undefined, d => foundAtX4.push(d));
+      assert.strictEqual(foundAtX4.length, 0);
+
+      const foundAtX5: typeof decoration[] = [];
+      service.forEachDecorationAtCell(5, 5, undefined, d => foundAtX5.push(d));
+      assert.strictEqual(foundAtX5.length, 1);
+
+      const foundAtX7: typeof decoration[] = [];
+      service.forEachDecorationAtCell(7, 6, undefined, d => foundAtX7.push(d));
+      assert.strictEqual(foundAtX7.length, 1);
+
+      const foundAtX8: typeof decoration[] = [];
+      service.forEachDecorationAtCell(8, 5, undefined, d => foundAtX8.push(d));
+      assert.strictEqual(foundAtX8.length, 0);
+    });
+  });
+
+  describe('getDecorationsAtCell', () => {
+    it('should find decoration with height > 1 on subsequent lines', () => {
+      const service = new DecorationService();
+      const decoration = service.registerDecoration({
+        marker: createFakeMarker(5),
+        width: 10,
+        height: 3
+      });
+      assert.ok(decoration);
+
+      assert.strictEqual([...service.getDecorationsAtCell(0, 5)].length, 1);
+      assert.strictEqual([...service.getDecorationsAtCell(0, 6)].length, 1);
+      assert.strictEqual([...service.getDecorationsAtCell(0, 7)].length, 1);
+      assert.strictEqual([...service.getDecorationsAtCell(0, 8)].length, 0);
+    });
+  });
 });