Fix bug during registration of generating targets

Fixes a bug where if the generating rule name is lexicographically after
the generated rule, changes in the generating rule are not picked up by
targets that depend on the generated rule.

Test plan:
Added unit test demonstrating buggy behavior.

Author: KevinJiao

src/main/java/com/bazel_diff/TargetHashingClient.java

@@ -166,13 +166,16 @@ private Map<String, String> hashAllTargets(byte[] seedHash, Map<String, BazelSou
             if (targetName == null) {
                 continue;
             }
-            if(target.hasGeneratedFile()) {
-                allRulesMap.put(targetName, allRulesMap.get(target.getGeneratingRuleName()));
-            }
             if(target.hasRule()) {
                 allRulesMap.put(targetName, target.getRule());
             }
         }
+        for (BazelTarget target: allTargets) {
+            if(target.hasGeneratedFile()) {
+                allRulesMap.put(getNameForTarget(target), allRulesMap.get(target.getGeneratingRuleName()));
+            }
+        }
+
         for (BazelTarget target : allTargets) {
             String targetName = getNameForTarget(target);
             if (targetName == null) {

test/java/com/bazel_diff/TargetHashingClientImplTests.java

@@ -122,6 +122,40 @@ public void hashAllBazelTargets_ruleTargets_ruleInputsWithSelfInput() throws IOE
         }
     }
 
+    @Test
+    public void HashAllBazelTargets_generatedTargets() throws IOException, NoSuchAlgorithmException {
+        BazelTarget generator = createRuleTarget("rule1", new ArrayList<String>(), "rule1Digest");
+        BazelTarget target = createGeneratedTarget("rule0", "rule1");
+
+        List<String> ruleInputs = new ArrayList<>();
+        ruleInputs.add("rule0");
+        BazelTarget rule3 = createRuleTarget("rule3", ruleInputs, "digest");
+
+        String oldHash = "";
+        String newHash = "";
+
+        when(bazelClientMock.queryAllTargets()).thenReturn(Arrays.asList(rule3, target, generator));
+        TargetHashingClientImpl client = new TargetHashingClientImpl(bazelClientMock, filesClientMock);
+        try {
+            Map<String, String> hash = client.hashAllBazelTargetsAndSourcefiles(new HashSet<>());
+            assertEquals(3, hash.size());
+            oldHash = hash.get("rule3");
+        } catch (IOException | NoSuchAlgorithmException e) {
+            fail(e.getMessage());
+        }
+
+        when(generator.getRule().getDigest()).thenReturn("newDigest".getBytes());
+        try {
+            Map<String, String> hash = client.hashAllBazelTargetsAndSourcefiles(new HashSet<>());
+            assertEquals(3, hash.size());
+            newHash = hash.get("rule3");
+        } catch (IOException | NoSuchAlgorithmException e) {
+            fail(e.getMessage());
+        }
+
+        assertNotEquals(oldHash, newHash);
+    }
+
     private BazelTarget createRuleTarget(String ruleName, List<String> ruleInputs, String ruleDigest) throws NoSuchAlgorithmException {
         BazelTarget target = mock(BazelTarget.class);
         BazelRule rule = mock(BazelRule.class);
@@ -149,4 +183,14 @@ private BazelSourceFileTarget createSourceFileTarget(String name, String digest)
         when(target.getDigest()).thenReturn(digest.getBytes());
         return target;
     }
+
+    private BazelTarget createGeneratedTarget(String name, String generatingRuleName) throws NoSuchAlgorithmException {
+        BazelTarget target = mock(BazelTarget.class);
+        when(target.hasRule()).thenReturn(false);
+        when(target.hasSourceFile()).thenReturn(false);
+        when(target.hasGeneratedFile()).thenReturn(true);
+        when(target.getGeneratedFileName()).thenReturn(name);
+        when(target.getGeneratingRuleName()).thenReturn(generatingRuleName);
+        return target;
+    }
 }