Introduce InputStream{Read,Skip}NBytes Refaster rules (#993)

PicnicSupermarket · Feb 13, 2024 · c2365c0 · c2365c0
1 parent 1d0d1d6
commit c2365c0
Show file tree

Hide file tree

Showing 3 changed files with 40 additions and 2 deletions.
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/InputStreamRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/InputStreamRules.java
@@ -9,8 +9,6 @@
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /** Refaster rules related to expressions dealing with {@link InputStream}s. */
-// XXX: Add a rule for `ByteStreams.skipFully(in, n)` -> `in.skipNBytes(n)` once we have a way to
-// target JDK 12+ APIs.
 @OnlineDocumentation
 final class InputStreamRules {
   private InputStreamRules() {}
@@ -38,4 +36,28 @@ byte[] after(InputStream in) throws IOException {
       return in.readAllBytes();
     }
   }
+
+  static final class InputStreamReadNBytes {
+    @BeforeTemplate
+    byte[] before(InputStream in, int n) throws IOException {
+      return ByteStreams.limit(in, n).readAllBytes();
+    }
+
+    @AfterTemplate
+    byte[] after(InputStream in, int n) throws IOException {
+      return in.readNBytes(n);
+    }
+  }
+
+  static final class InputStreamSkipNBytes {
+    @BeforeTemplate
+    void before(InputStream in, long n) throws IOException {
+      ByteStreams.skipFully(in, n);
+    }
+
+    @AfterTemplate
+    void after(InputStream in, long n) throws IOException {
+      in.skipNBytes(n);
+    }
+  }
 }
diff --git a/...ib/src/test/resources/tech/picnic/errorprone/refasterrules/InputStreamRulesTestInput.java b/...ib/src/test/resources/tech/picnic/errorprone/refasterrules/InputStreamRulesTestInput.java
@@ -20,4 +20,12 @@ long testInputStreamTransferTo() throws IOException {
   byte[] testInputStreamReadAllBytes() throws IOException {
     return ByteStreams.toByteArray(new ByteArrayInputStream(new byte[0]));
   }
+
+  byte[] testInputStreamReadNBytes() throws IOException {
+    return ByteStreams.limit(new ByteArrayInputStream(new byte[0]), 0).readAllBytes();
+  }
+
+  void testInputStreamSkipNBytes() throws IOException {
+    ByteStreams.skipFully(new ByteArrayInputStream(new byte[0]), 0);
+  }
 }
diff --git a/...b/src/test/resources/tech/picnic/errorprone/refasterrules/InputStreamRulesTestOutput.java b/...b/src/test/resources/tech/picnic/errorprone/refasterrules/InputStreamRulesTestOutput.java
@@ -20,4 +20,12 @@ long testInputStreamTransferTo() throws IOException {
   byte[] testInputStreamReadAllBytes() throws IOException {
     return new ByteArrayInputStream(new byte[0]).readAllBytes();
   }
+
+  byte[] testInputStreamReadNBytes() throws IOException {
+    return new ByteArrayInputStream(new byte[0]).readNBytes(0);
+  }
+
+  void testInputStreamSkipNBytes() throws IOException {
+    new ByteArrayInputStream(new byte[0]).skipNBytes(0);
+  }
 }