implement yeast

src/test/java/io/socket/yeast/YeastTest.java

@@ -0,0 +1,76 @@
+package io.socket.yeast;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+import java.util.Arrays;
+import java.util.Date;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.not;
+import static org.junit.Assert.assertThat;
+
+;
+
+@RunWith(JUnit4.class)
+public class YeastTest {
+
+    private void waitUntilNextMillisecond() {
+        long now = new Date().getTime();
+        while (new Date().getTime() == now) { /* do nothing */ }
+    }
+
+    @Test
+    public void prependsIteratedSeedWhenSamePreviousId() {
+        waitUntilNextMillisecond();
+
+        String[] ids = new String[] { Yeast.yeast(), Yeast.yeast(), Yeast.yeast() };
+        assertThat(ids[0], not(containsString(".")));
+        assertThat(ids[1], containsString(".0"));
+        assertThat(ids[2], containsString(".1"));
+    }
+
+    @Test
+    public void resetsTheSeed() {
+        waitUntilNextMillisecond();
+
+        String[] ids = new String[] { Yeast.yeast(), Yeast.yeast(), Yeast.yeast() };
+        assertThat(ids[0], not(containsString(".")));
+        assertThat(ids[1], containsString(".0"));
+        assertThat(ids[2], containsString(".1"));
+
+        waitUntilNextMillisecond();
+
+        ids = new String[] { Yeast.yeast(), Yeast.yeast(), Yeast.yeast() };
+        assertThat(ids[0], not(containsString(".")));
+        assertThat(ids[1], containsString(".0"));
+        assertThat(ids[2], containsString(".1"));
+    }
+
+    @Test
+    public void doesNotCollide() {
+        int length = 30000;
+        String[] ids = new String[length];
+
+        for (int i = 0; i < length; i++) ids[i] = Yeast.yeast();
+
+        Arrays.sort(ids);
+
+        for (int i = 0; i < length - 1; i++) {
+            assertThat(ids[i], not(equalTo(ids[i + 1])));
+        }
+    }
+
+    @Test
+    public void canConvertIdToTimestamp() {
+        waitUntilNextMillisecond();
+
+        long now = new Date().getTime();
+        String id = Yeast.yeast();
+
+        assertThat(Yeast.encode(now), equalTo(id));
+        assertThat(Yeast.decode(id), equalTo(now));
+    }
+}