Extend StepVerifierStepIdentity Refaster rule (#541)

By flagging expressions of the form `step.expectNextCount(0)`.
PicnicSupermarket · Mar 27, 2023 · 57cd084 · 57cd084
1 parent 0b3be1b
commit 57cd084
Show file tree

Hide file tree

Showing 3 changed files with 11 additions and 7 deletions.
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
@@ -1204,12 +1204,14 @@ StepVerifier.FirstStep<? extends T> after(Flux<T> flux) {
     }
   }
 
-  /** Don't unnecessarily call {@link StepVerifier.Step#expectNext(Object[])}. */
-  static final class StepVerifierStepExpectNextEmpty<T> {
+  /** Don't unnecessarily have {@link StepVerifier.Step} expect no elements. */
+  // XXX: Given an `IsEmpty` matcher that identifies a wide range of guaranteed-empty `Iterable`
+  // expressions, consider also simplifying `step.expectNextSequence(someEmptyIterable)`.
+  static final class StepVerifierStepIdentity<T> {
     @BeforeTemplate
     @SuppressWarnings("unchecked")
     StepVerifier.Step<T> before(StepVerifier.Step<T> step) {
-      return step.expectNext();
+      return Refaster.anyOf(step.expectNext(), step.expectNextCount(0));
     }
 
     @AfterTemplate

diff --git a/...ontrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestInput.java b/...ontrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestInput.java
@@ -389,8 +389,10 @@ StepVerifier.FirstStep<Integer> testStepVerifierFromFlux() {
     return StepVerifier.create(Flux.just(1));
   }
 
-  StepVerifier.Step<Integer> testStepVerifierStepExpectNextEmpty() {
-    return StepVerifier.create(Mono.just(0)).expectNext();
+  ImmutableSet<StepVerifier.Step<Integer>> testStepVerifierStepIdentity() {
+    return ImmutableSet.of(
+        StepVerifier.create(Mono.just(1)).expectNext(),
+        StepVerifier.create(Mono.just(2)).expectNextCount(0L));
   }
 
   ImmutableSet<StepVerifier.Step<String>> testStepVerifierStepExpectNext() {

diff --git a/...ntrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestOutput.java b/...ntrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestOutput.java
@@ -377,8 +377,8 @@ StepVerifier.FirstStep<Integer> testStepVerifierFromFlux() {
     return Flux.just(1).as(StepVerifier::create);
   }
 
-  StepVerifier.Step<Integer> testStepVerifierStepExpectNextEmpty() {
-    return StepVerifier.create(Mono.just(0));
+  ImmutableSet<StepVerifier.Step<Integer>> testStepVerifierStepIdentity() {
+    return ImmutableSet.of(StepVerifier.create(Mono.just(1)), StepVerifier.create(Mono.just(2)));
   }
 
   ImmutableSet<StepVerifier.Step<String>> testStepVerifierStepExpectNext() {