PR comments - add proper compatibility with Mono.empty publisher

PicnicSupermarket · Dec 12, 2023 · 1c96be3 · 1c96be3
1 parent 56e9e39
commit 1c96be3
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Showing 2 changed files with 21 additions and 8 deletions.
diff --git a/...rone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MonoZipOfMonoVoidUsage.java b/...rone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/MonoZipOfMonoVoidUsage.java
@@ -3,8 +3,11 @@
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
 import static com.google.errorprone.BugPattern.StandardTags.LIKELY_ERROR;
+import static com.google.errorprone.matchers.ChildMultiMatcher.MatchType.AT_LEAST_ONE;
 import static com.google.errorprone.matchers.Matchers.allOf;
 import static com.google.errorprone.matchers.Matchers.anyOf;
+import static com.google.errorprone.matchers.Matchers.argument;
+import static com.google.errorprone.matchers.Matchers.hasArguments;
 import static com.google.errorprone.matchers.Matchers.instanceMethod;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
 import static com.google.errorprone.matchers.Matchers.toType;
@@ -73,11 +76,18 @@ public final class MonoZipOfMonoVoidUsage extends BugChecker
               toType(MethodInvocationTree.class, hasGenericArgumentOfExactType(MONO_VOID_TYPE))),
           allOf(
               instanceMethod().onDescendantOf(MONO).named("zipWith"),
-              toType(MethodInvocationTree.class, staticMethod().onClass(MONO).named("empty"))),
+              toType(
+                  MethodInvocationTree.class,
+                  argument(0, staticMethod().onClass(MONO).named("empty")))),
           onClassWithMethodName(MONO_VOID_TYPE, "zipWith"),
           allOf(
               staticMethod().onClass(MONO).named("zip"),
-              toType(MethodInvocationTree.class, hasGenericArgumentOfExactType(MONO_VOID_TYPE))));
+              toType(MethodInvocationTree.class, hasGenericArgumentOfExactType(MONO_VOID_TYPE))),
+          allOf(
+              staticMethod().onClass(MONO).named("zip"),
+              toType(
+                  MethodInvocationTree.class,
+                  hasArguments(AT_LEAST_ONE, staticMethod().onClass(MONO).named("empty")))));
 
   /** Instantiates a new {@link MonoZipOfMonoVoidUsage} instance. */
   public MonoZipOfMonoVoidUsage() {}

diff --git a/...-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/MonoZipOfMonoVoidUsageTest.java b/...-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/MonoZipOfMonoVoidUsageTest.java
@@ -6,12 +6,8 @@
 
 final class MonoZipOfMonoVoidUsageTest {
   /**
-   * Line 44 won't be reported as a bug. It's quite hard to catch this case as {@code Mono.empty()}
-   * yields {@code Mono<Object>}, so matcher will be too wide. Additionally, it's not expected to
-   * occur in the real production code.
-   *
-   * <p>Line 25 needed to simulate the unwanted intrinsic operations, which are not intended to be
-   * processed by the rule.
+   * Line 21 is needed to simulate the unwanted intrinsic operations, which are not intended to be
+   * processed by the rule but will be scanned anyway.
    */
   @Test
   void identification() {
@@ -41,6 +37,9 @@ void identification() {
             "    Mono.zip(d, c, b, a);",
             "    Mono.zip(d, c, b);",
             "    b.zipWith(b).zipWith(c).map(entry -> entry);",
+            "    // BUG: Diagnostic contains: `Mono#zip` and `Mono#zipWith` should not be executed against",
+            "    // `Mono#empty` or `Mono<Void>` parameter; please revisit the parameters used and make sure to",
+            "    // supply correct publishers instead",
             "    Mono.zip(d, Mono.empty());",
             "    c.zipWith(b);",
             "    c.zipWith(d);",
@@ -61,6 +60,10 @@ void identification() {
             "    // `Mono#empty` or `Mono<Void>` parameter; please revisit the parameters used and make sure to",
             "    // supply correct publishers instead",
             "    a.zipWith(c, (first, second) -> second);",
+            "    // BUG: Diagnostic contains: `Mono#zip` and `Mono#zipWith` should not be executed against",
+            "    // `Mono#empty` or `Mono<Void>` parameter; please revisit the parameters used and make sure to",
+            "    // supply correct publishers instead",
+            "    c.zipWith(Mono.empty());",
             "  }",
             "",
             "  private Mono<Integer> publisher() {",