Apply in more cases

PicnicSupermarket · Oct 23, 2023 · 3c6a1d8 · 3c6a1d8
1 parent 1928545
commit 3c6a1d8
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Showing 5 changed files with 50 additions and 19 deletions.
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ComparatorRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ComparatorRules.java
@@ -185,8 +185,8 @@ Comparator<T> after(Comparator<T> cmp, ToLongFunction<? super T> function) {
   }
 
   /**
-   * Where applicable, prefer {@link Comparator#naturalOrder()} over {@link Function#identity()}, as
-   * it more clearly states intent.
+   * Where applicable, prefer {@link Comparator#naturalOrder()} over identity function-based
+   * comparisons, as the former more clearly states intent.
    */
   static final class ThenComparingNaturalOrder<T extends Comparable<? super T>> {
     @BeforeTemplate

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
@@ -595,11 +595,16 @@ Flux<S> after(Flux<T> flux, Function<? super T, ? extends P> function, int prefe
   }
 
   /** Avoid contrived alternatives to {@link Mono#flatMapIterable(Function)}. */
-  static final class MonoFlatMapIterable<T, S> {
+  static final class MonoFlatMapIterable<T, S, I extends Iterable<? extends S>> {
     @BeforeTemplate
-    Flux<S> before(Mono<T> mono, Function<? super T, ? extends Iterable<? extends S>> function) {
+    Flux<S> before(
+        Mono<T> mono,
+        Function<? super T, I> function,
+        @Matches(IsIdentityOperation.class)
+            Function<? super I, ? extends Iterable<? extends S>> identityOperation) {
       return Refaster.anyOf(
-          mono.map(function).flatMapIterable(identity()), mono.flux().concatMapIterable(function));
+          mono.map(function).flatMapIterable(identityOperation),
+          mono.flux().concatMapIterable(function));
     }
 
     @AfterTemplate
@@ -629,11 +634,15 @@ Flux<T> after(Mono<S> mono) {
    * Prefer {@link Flux#concatMapIterable(Function)} over alternatives with less clear syntax or
    * semantics.
    */
-  static final class FluxConcatMapIterable<T, S> {
+  static final class FluxConcatMapIterable<T, S, I extends Iterable<? extends S>> {
     @BeforeTemplate
-    Flux<S> before(Flux<T> flux, Function<? super T, ? extends Iterable<? extends S>> function) {
+    Flux<S> before(
+        Flux<T> flux,
+        Function<? super T, I> function,
+        @Matches(IsIdentityOperation.class)
+            Function<? super I, ? extends Iterable<? extends S>> identityOperation) {
       return Refaster.anyOf(
-          flux.flatMapIterable(function), flux.map(function).concatMapIterable(identity()));
+          flux.flatMapIterable(function), flux.map(function).concatMapIterable(identityOperation));
     }
 
     @AfterTemplate
@@ -646,13 +655,17 @@ Flux<S> after(Flux<T> flux, Function<? super T, ? extends Iterable<? extends S>>
    * Prefer {@link Flux#concatMapIterable(Function, int)} over alternatives with less clear syntax
    * or semantics.
    */
-  static final class FluxConcatMapIterableWithPrefetch<T, S> {
+  static final class FluxConcatMapIterableWithPrefetch<T, S, I extends Iterable<? extends S>> {
     @BeforeTemplate
     Flux<S> before(
-        Flux<T> flux, Function<? super T, ? extends Iterable<? extends S>> function, int prefetch) {
+        Flux<T> flux,
+        Function<? super T, I> function,
+        int prefetch,
+        @Matches(IsIdentityOperation.class)
+            Function<? super I, ? extends Iterable<? extends S>> identityOperation) {
       return Refaster.anyOf(
           flux.flatMapIterable(function, prefetch),
-          flux.map(function).concatMapIterable(identity(), prefetch));
+          flux.map(function).concatMapIterable(identityOperation, prefetch));
     }
 
     @AfterTemplate

diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/StreamRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/StreamRules.java
@@ -357,6 +357,8 @@ boolean before(Stream<T> stream, Predicate<? super T> predicate) {
           stream.filter(predicate).findAny().isEmpty());
     }
 
+    // XXX: Consider extending `@Matches(IsIdentityOperation.class)` such that it can replace this
+    // template's `Refaster.anyOf` usage.
     @BeforeTemplate
     boolean before2(
         Stream<T> stream,
@@ -395,6 +397,8 @@ boolean before(Stream<T> stream, Predicate<? super T> predicate) {
           !stream.noneMatch(predicate), stream.filter(predicate).findAny().isPresent());
     }
 
+    // XXX: Consider extending `@Matches(IsIdentityOperation.class)` such that it can replace this
+    // template's `Refaster.anyOf` usage.
     @BeforeTemplate
     boolean before2(
         Stream<T> stream,
@@ -415,6 +419,8 @@ boolean before(Stream<T> stream, Predicate<? super T> predicate) {
       return stream.noneMatch(Refaster.anyOf(not(predicate), predicate.negate()));
     }
 
+    // XXX: Consider extending `@Matches(IsIdentityOperation.class)` such that it can replace this
+    // template's `Refaster.anyOf` usage.
     @BeforeTemplate
     boolean before2(
         Stream<T> stream,

diff --git a/...ontrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestInput.java b/...ontrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestInput.java
@@ -219,7 +219,9 @@ ImmutableSet<Flux<Integer>> testFluxConcatMapWithPrefetch() {
   ImmutableSet<Flux<Integer>> testMonoFlatMapIterable() {
     return ImmutableSet.of(
         Mono.just(1).map(ImmutableSet::of).flatMapIterable(identity()),
-        Mono.just(2).flux().concatMapIterable(ImmutableSet::of));
+        Mono.just(2).map(ImmutableSet::of).flatMapIterable(v -> v),
+        Mono.just(3).map(ImmutableSet::of).flatMapIterable(v -> ImmutableSet.of()),
+        Mono.just(4).flux().concatMapIterable(ImmutableSet::of));
   }
 
   Flux<Integer> testMonoFlatMapIterableIdentity() {
@@ -229,13 +231,17 @@ Flux<Integer> testMonoFlatMapIterableIdentity() {
   ImmutableSet<Flux<Integer>> testFluxConcatMapIterable() {
     return ImmutableSet.of(
         Flux.just(1).flatMapIterable(ImmutableList::of),
-        Flux.just(2).map(ImmutableList::of).concatMapIterable(identity()));
+        Flux.just(2).map(ImmutableList::of).concatMapIterable(identity()),
+        Flux.just(3).map(ImmutableList::of).concatMapIterable(v -> v),
+        Flux.just(4).map(ImmutableList::of).concatMapIterable(v -> ImmutableSet.of()));
   }
 
   ImmutableSet<Flux<Integer>> testFluxConcatMapIterableWithPrefetch() {
     return ImmutableSet.of(
-        Flux.just(1).flatMapIterable(ImmutableList::of, 3),
-        Flux.just(2).map(ImmutableList::of).concatMapIterable(identity(), 3));
+        Flux.just(1).flatMapIterable(ImmutableList::of, 5),
+        Flux.just(2).map(ImmutableList::of).concatMapIterable(identity(), 5),
+        Flux.just(3).map(ImmutableList::of).concatMapIterable(v -> v, 5),
+        Flux.just(4).map(ImmutableList::of).concatMapIterable(v -> ImmutableSet.of(), 5));
   }
 
   Flux<String> testMonoFlatMapToFlux() {

diff --git a/...ntrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestOutput.java b/...ntrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestOutput.java
@@ -222,7 +222,9 @@ ImmutableSet<Flux<Integer>> testFluxConcatMapWithPrefetch() {
   ImmutableSet<Flux<Integer>> testMonoFlatMapIterable() {
     return ImmutableSet.of(
         Mono.just(1).flatMapIterable(ImmutableSet::of),
-        Mono.just(2).flatMapIterable(ImmutableSet::of));
+        Mono.just(2).flatMapIterable(ImmutableSet::of),
+        Mono.just(3).map(ImmutableSet::of).flatMapIterable(v -> ImmutableSet.of()),
+        Mono.just(4).flatMapIterable(ImmutableSet::of));
   }
 
   Flux<Integer> testMonoFlatMapIterableIdentity() {
@@ -232,13 +234,17 @@ Flux<Integer> testMonoFlatMapIterableIdentity() {
   ImmutableSet<Flux<Integer>> testFluxConcatMapIterable() {
     return ImmutableSet.of(
         Flux.just(1).concatMapIterable(ImmutableList::of),
-        Flux.just(2).concatMapIterable(ImmutableList::of));
+        Flux.just(2).concatMapIterable(ImmutableList::of),
+        Flux.just(3).concatMapIterable(ImmutableList::of),
+        Flux.just(4).map(ImmutableList::of).concatMapIterable(v -> ImmutableSet.of()));
   }
 
   ImmutableSet<Flux<Integer>> testFluxConcatMapIterableWithPrefetch() {
     return ImmutableSet.of(
-        Flux.just(1).concatMapIterable(ImmutableList::of, 3),
-        Flux.just(2).concatMapIterable(ImmutableList::of, 3));
+        Flux.just(1).concatMapIterable(ImmutableList::of, 5),
+        Flux.just(2).concatMapIterable(ImmutableList::of, 5),
+        Flux.just(3).concatMapIterable(ImmutableList::of, 5),
+        Flux.just(4).map(ImmutableList::of).concatMapIterable(v -> ImmutableSet.of(), 5));
   }
 
   Flux<String> testMonoFlatMapToFlux() {