1 files changed, 79 insertions, 0 deletions
diff --git a/chromium/base/android/junit/src/org/chromium/base/supplier/OneshotSupplierImplTest.java b/chromium/base/android/junit/src/org/chromium/base/supplier/OneshotSupplierImplTest.java
new file mode 100644
index 00000000000..b00cb18fe87
--- /dev/null
+++ b/chromium/base/android/junit/src/org/chromium/base/supplier/OneshotSupplierImplTest.java
@@ -0,0 +1,79 @@
+// Copyright 2020 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.base.supplier;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.mockito.Mockito.verify;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.MockitoAnnotations;
+import org.mockito.Spy;
+import org.robolectric.annotation.Config;
+import org.robolectric.annotation.LooperMode;
+import org.robolectric.shadows.ShadowProcess;
+
+import org.chromium.base.Callback;
+import org.chromium.base.test.BaseRobolectricTestRunner;
+
+/**
+ * Unit tests for {@link OneshotSupplierImpl}.
+ */
+@RunWith(BaseRobolectricTestRunner.class)
+@Config(shadows = {ShadowProcess.class})
+@LooperMode(LooperMode.Mode.LEGACY)
+public class OneshotSupplierImplTest {
+    private OneshotSupplierImpl<String> mSupplier = new OneshotSupplierImpl<>();
+
+    @Spy
+    private Callback<String> mCallback1;
+    @Spy
+    private Callback<String> mCallback2;
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+    }
+
+    @Test
+    public void testSet() {
+        assertNull(mSupplier.onAvailable(mCallback1));
+        assertNull(mSupplier.onAvailable(mCallback2));
+        mSupplier.set("answer");
+
+        verify(mCallback1).onResult("answer");
+        verify(mCallback2).onResult("answer");
+    }
+
+    @Test
+    public void testSetBeforeAddObserver() {
+        mSupplier.set("answer");
+
+        assertEquals("answer", mSupplier.onAvailable(mCallback1));
+        assertEquals("answer", mSupplier.onAvailable(mCallback2));
+
+        verify(mCallback1).onResult("answer");
+        verify(mCallback2).onResult("answer");
+    }
+
+    @Test
+    public void testInterleaved() {
+        assertNull(mSupplier.onAvailable(mCallback1));
+        mSupplier.set("answer");
+        assertEquals("answer", mSupplier.onAvailable(mCallback2));
+
+        verify(mCallback1).onResult("answer");
+        verify(mCallback2).onResult("answer");
+    }
+
+    @Test
+    public void testGet() {
+        assertNull(mSupplier.get());
+        mSupplier.set("answer");
+        assertEquals("answer", mSupplier.get());
+    }
+}