Add unit tests for Util and TimelineMetricsRecorder

UtilTest (23 tests): covers validateTimeFormat (canonical/malformed/null/label propagation), getTimeStamp (basic, millisecond precision, zero-padding, malformed/null rejection), and getTimeDifference (zero/positive/negative/sub-minute/combined-units/malformed/null). Skips the JDBC-bound factory methods which require a live PostgreSQL instance.

TimelineMetricsRecorderTest (18 tests): covers per-step capture (density, avg/max degree, avg weight, isolated nodes, component count, per-category counts that only tally edges present in the graph), churn accounting (new/lost nodes/edges across steps), CSV export to file and string with header + RFC-4180 escaping of labels containing commas/quotes, trend analysis (peaks, averages, population std dev, category min/max/avg), phase-transition detection at the default threshold and respect for a custom threshold, validation on setPhaseThreshold (0.0 and >1.0 rejected, 1.0 boundary accepted), null-graph rejection, clear() resetting both step index and churn baseline, and snapshots list immutability.

Author: Zalenix

Gvisual/test/app/UtilTest.java

@@ -0,0 +1,187 @@
+package app;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ * Unit tests for the pure (non-database) helpers on {@link Util}:
+ *
+ * <ul>
+ *   <li>{@link Util#validateTimeFormat(String, String)}</li>
+ *   <li>{@link Util#getTimeStamp(String, String, String)}</li>
+ *   <li>{@link Util#getTimeDifference(String, String)}</li>
+ * </ul>
+ *
+ * <p>The database-bound methods ({@code getAppConnection},
+ * {@code getAzialaConnection}) are intentionally NOT exercised here \u2014
+ * they require a live PostgreSQL instance and credentials from the
+ * environment, which is outside the scope of unit tests.</p>
+ *
+ * <p>The trace format used throughout is {@code "HH.MM:SS.mmm"}:
+ * dot-separated hours/minutes and seconds/millis, with a single colon
+ * between the two halves.</p>
+ */
+public class UtilTest {
+
+    // ============================================================
+    //  validateTimeFormat
+    // ============================================================
+
+    @Test
+    public void validateTimeFormat_acceptsCanonicalFormat() {
+        // Should not throw.
+        Util.validateTimeFormat("10.30:15.000", "endTime");
+        Util.validateTimeFormat("00.00:00.000", "endTime");
+        Util.validateTimeFormat("23.59:59.999", "endTime");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void validateTimeFormat_rejectsNull() {
+        Util.validateTimeFormat(null, "endTime");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void validateTimeFormat_rejectsEmpty() {
+        Util.validateTimeFormat("", "endTime");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void validateTimeFormat_rejectsMissingColon() {
+        Util.validateTimeFormat("10.30.15.000", "endTime");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void validateTimeFormat_rejectsMultipleColons() {
+        // Two colons -> split() length != 2 -> rejected.
+        Util.validateTimeFormat("10:30:15.000", "endTime");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void validateTimeFormat_rejectsMissingDotInLeftHalf() {
+        // "10:15.000" -> left half "10" has no dot -> rejected
+        Util.validateTimeFormat("10:15.000", "endTime");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void validateTimeFormat_rejectsMissingDotInRightHalf() {
+        // "10.30:15" -> right half "15" has no dot -> rejected
+        Util.validateTimeFormat("10.30:15", "endTime");
+    }
+
+    @Test
+    public void validateTimeFormat_errorMessageIncludesLabel() {
+        try {
+            Util.validateTimeFormat(null, "myCustomLabel");
+            fail("expected IllegalArgumentException");
+        } catch (IllegalArgumentException ex) {
+            assertTrue("error message should reference the label, got: " + ex.getMessage(),
+                ex.getMessage().contains("myCustomLabel"));
+        }
+    }
+
+    // ============================================================
+    //  getTimeStamp
+    // ============================================================
+
+    @Test
+    public void getTimeStamp_basicConversion() {
+        // month="03", date="15", time="10.30:15.000"
+        // -> "2011-03-15 10:30:15.000"
+        String ts = Util.getTimeStamp("03", "15", "10.30:15.000");
+        assertEquals("2011-03-15 10:30:15.000", ts);
+    }
+
+    @Test
+    public void getTimeStamp_preservesMillisecondsExactly() {
+        String ts = Util.getTimeStamp("12", "31", "23.59:59.987");
+        assertEquals("2011-12-31 23:59:59.987", ts);
+    }
+
+    @Test
+    public void getTimeStamp_zeroPaddedZerothSecond() {
+        String ts = Util.getTimeStamp("01", "01", "00.00:00.000");
+        assertEquals("2011-01-01 00:00:00.000", ts);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void getTimeStamp_rejectsMalformedTime() {
+        // No colon \u2192 validateTimeFormat throws \u2192 propagated out.
+        Util.getTimeStamp("03", "15", "not-a-time");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void getTimeStamp_rejectsNullTime() {
+        Util.getTimeStamp("03", "15", null);
+    }
+
+    // ============================================================
+    //  getTimeDifference
+    // ============================================================
+
+    @Test
+    public void getTimeDifference_sameTimeIsZero() {
+        assertEquals(0.0f,
+            Util.getTimeDifference("10.30:15.000", "10.30:15.000"),
+            1e-4f);
+    }
+
+    @Test
+    public void getTimeDifference_oneHourApart() {
+        // 11:30:00 - 10:30:00 = 60 minutes
+        assertEquals(60.0f,
+            Util.getTimeDifference("11.30:00.000", "10.30:00.000"),
+            1e-3f);
+    }
+
+    @Test
+    public void getTimeDifference_oneMinuteApart() {
+        // 10:31:00 - 10:30:00 = 1 minute
+        assertEquals(1.0f,
+            Util.getTimeDifference("10.31:00.000", "10.30:00.000"),
+            1e-3f);
+    }
+
+    @Test
+    public void getTimeDifference_thirtySecondsApart() {
+        // 30 seconds = 0.5 minutes
+        assertEquals(0.5f,
+            Util.getTimeDifference("10.30:30.000", "10.30:00.000"),
+            1e-3f);
+    }
+
+    @Test
+    public void getTimeDifference_negativeWhenEndBeforeStart() {
+        // 10:30 - 11:30 = -60 minutes
+        assertEquals(-60.0f,
+            Util.getTimeDifference("10.30:00.000", "11.30:00.000"),
+            1e-3f);
+    }
+
+    @Test
+    public void getTimeDifference_combinedHoursMinutesSeconds() {
+        // 11:31:30 - 10:30:00 = 60 + 1 + 0.5 = 61.5 minutes
+        assertEquals(61.5f,
+            Util.getTimeDifference("11.31:30.000", "10.30:00.000"),
+            1e-3f);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void getTimeDifference_rejectsMalformedEndTime() {
+        Util.getTimeDifference("not-a-time", "10.30:00.000");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void getTimeDifference_rejectsMalformedStartTime() {
+        Util.getTimeDifference("10.30:00.000", "still-not-a-time");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void getTimeDifference_rejectsNullEnd() {
+        Util.getTimeDifference(null, "10.30:00.000");
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void getTimeDifference_rejectsNullStart() {
+        Util.getTimeDifference("10.30:00.000", null);
+    }
+}