new file mode 100644
--- /dev/null
+++ b/mobile/android/tests/background/junit4/src/org/mozilla/gecko/telemetry/pings/TestTelemetryPingBuilder.java
@@ -0,0 +1,92 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+package org.mozilla.gecko.telemetry.pings;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mozilla.gecko.background.testhelpers.TestRunner;
+
+import static org.junit.Assert.*;
+
+/**
+ * Unit test methods of the {@link TelemetryPingBuilder} class.
+ */
+@RunWith(TestRunner.class)
+public class TestTelemetryPingBuilder {
+    @Test
+    public void testMandatoryFieldsNone() {
+        final NoMandatoryFieldsBuilder builder = new NoMandatoryFieldsBuilder();
+        builder.setNonMandatoryField();
+        assertNotNull("Builder does not throw and returns a non-null value", builder.build());
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testMandatoryFieldsMissing() {
+        final MandatoryFieldsBuilder builder = new MandatoryFieldsBuilder();
+        builder.setNonMandatoryField()
+                .build(); // should throw
+    }
+
+    @Test
+    public void testMandatoryFieldsIncluded() {
+        final MandatoryFieldsBuilder builder = new MandatoryFieldsBuilder();
+        builder.setNonMandatoryField()
+                .setMandatoryField();
+        assertNotNull("Builder does not throw and returns non-null value", builder.build());
+    }
+
+    private static class NoMandatoryFieldsBuilder extends TelemetryPingBuilder {
+        public NoMandatoryFieldsBuilder() {
+            super("");
+        }
+
+        @Override
+        String getDocType() {
+            return "";
+        }
+
+        @Override
+        String[] getMandatoryFields() {
+            return new String[0];
+        }
+
+        public NoMandatoryFieldsBuilder setNonMandatoryField() {
+            payload.put("non-mandatory", true);
+            return this;
+        }
+    }
+
+    private static class MandatoryFieldsBuilder extends TelemetryPingBuilder {
+        private static final String MANDATORY_FIELD = "mandatory-field";
+
+        public MandatoryFieldsBuilder() {
+            super("");
+        }
+
+        @Override
+        String getDocType() {
+            return "";
+        }
+
+        @Override
+        String[] getMandatoryFields() {
+            return new String[] {
+                    MANDATORY_FIELD,
+            };
+        }
+
+        public MandatoryFieldsBuilder setNonMandatoryField() {
+            payload.put("non-mandatory", true);
+            return this;
+        }
+
+        public MandatoryFieldsBuilder setMandatoryField() {
+            payload.put(MANDATORY_FIELD, true);
+            return this;
+        }
+    }
+}