From 879ba3a5648a7f723207edfea1020a581b9392a4 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Tue, 30 Apr 2024 06:19:22 +0200
Subject: [PATCH] Introduce temporary file creation Refaster rules

---
 .../errorprone/refasterrules/FileRules.java   | 32 +++++++++++++++++++
 .../refasterrules/FileRulesTestInput.java     |  9 ++++++
 .../refasterrules/FileRulesTestOutput.java    |  9 ++++++
 3 files changed, 50 insertions(+)

diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/FileRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/FileRules.java
index bc230e0ae59..647d4015a2e 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/FileRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/FileRules.java
@@ -4,10 +4,12 @@
 
 import com.google.errorprone.refaster.annotation.AfterTemplate;
 import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import java.io.File;
 import java.io.IOException;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.attribute.FileAttribute;
 import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
 
 /** Refaster rules related to expressions dealing with files. */
@@ -40,4 +42,34 @@ String after(Path path) throws IOException {
       return Files.readString(path);
     }
   }
+
+  /** Prefer {@link File#createTempFile(String, String)} over more verbose alternatives. */
+  static final class FileCreateTempFile {
+    @BeforeTemplate
+    File before(String prefix, String suffix) throws IOException {
+      return File.createTempFile(prefix, suffix, null);
+    }
+
+    @AfterTemplate
+    File after(String prefix, String suffix) throws IOException {
+      return File.createTempFile(prefix, suffix);
+    }
+  }
+
+  /**
+   * Prefer {@link Files#createTempFile(String, String, FileAttribute[])} over {@link
+   * File#createTempFile(String, String)}, as the former creates files with more restrictive
+   * permissions.
+   */
+  static final class FilesCreateTempFileToFile {
+    @BeforeTemplate
+    File before(String prefix, String suffix) throws IOException {
+      return File.createTempFile(prefix, suffix);
+    }
+
+    @AfterTemplate
+    File after(String prefix, String suffix) throws IOException {
+      return Files.createTempFile(prefix, suffix).toFile();
+    }
+  }
 }
diff --git a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestInput.java b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestInput.java
index c33f3e679fc..110a73b6d40 100644
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestInput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestInput.java
@@ -1,5 +1,6 @@
 package tech.picnic.errorprone.refasterrules;
 
+import java.io.File;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
@@ -14,4 +15,12 @@ String testFilesReadStringWithCharset() throws IOException {
   String testFilesReadString() throws IOException {
     return Files.readString(Paths.get("foo"), StandardCharsets.UTF_8);
   }
+
+  File testFileCreateTempFile() throws IOException {
+    return File.createTempFile("foo", "bar", null);
+  }
+
+  File testFilesCreateTempFileToFile() throws IOException {
+    return File.createTempFile("foo", "bar");
+  }
 }
diff --git a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestOutput.java b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestOutput.java
index 5b516e31f9e..65237e881c3 100644
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestOutput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/FileRulesTestOutput.java
@@ -1,5 +1,6 @@
 package tech.picnic.errorprone.refasterrules;
 
+import java.io.File;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
@@ -14,4 +15,12 @@ String testFilesReadStringWithCharset() throws IOException {
   String testFilesReadString() throws IOException {
     return Files.readString(Paths.get("foo"));
   }
+
+  File testFileCreateTempFile() throws IOException {
+    return File.createTempFile("foo", "bar");
+  }
+
+  File testFilesCreateTempFileToFile() throws IOException {
+    return Files.createTempFile("foo", "bar").toFile();
+  }
 }