Fix file:copy to return error when target file exists without REPLACE_EXISTING

ballerina/Dependencies.toml

@@ -114,7 +114,7 @@ dependencies = [
 [[package]]
 org = "ballerina"
 name = "os"
-version = "1.10.0"
+version = "1.10.1"
 dependencies = [
 	{org = "ballerina", name = "io"},
 	{org = "ballerina", name = "jballerina.java"}

ballerina/tests/file-test.bal

@@ -244,8 +244,18 @@ function testCreateDirWithoutParentDir() {
     }
 }
 
-@test:Config {}
-function testCopyFile() {
+function RemoveCopySource() returns error? {
+    boolean|error isSourceExists = test(tmpdir + copyFile, EXISTS);
+    if isSourceExists is boolean && isSourceExists {
+        check remove(tmpdir + copyFile);
+    }
+}
+
+@test:Config {
+    before: RemoveCopySource,
+    dependsOn: [testRemove, testFileExists]
+}
+function testCopyFileToNonExistentFileReplaceFalse() {
     MetaData|error srcmetadata = getMetaData(srcFile);
     if srcmetadata is MetaData {
         srcFileLength = srcmetadata.size;
@@ -267,41 +277,54 @@ function testCopyFile() {
     }
 }
 
-@test:Config {dependsOn: [testCopyFile]}
-function testCopyFileReplaceFalse() {
-    MetaData|error srcMmetadata = getMetaData(srcModifiedFile);
-    if srcMmetadata is MetaData {
-        srcModifiedFileLength = srcMmetadata.size;
+@test:Config {dependsOn: [testCopyFileToNonExistentFileReplaceFalse]}
+function testCopyFileToExistingFileReplaceFalse() {
+    error? copyResult = copy(srcFile, tmpdir + copyFile);
+    if copyResult is error {
+        string expectedErrMsg = "The target file already exists";
+        test:assertTrue(copyResult.message().includes(expectedErrMsg));
     } else {
-        test:assertFail("Error retrieving source file size!");
+        test:assertFail("File copy succeeded to an existing file when replace false!");
     }
+}
 
-    error? copyResult = copy(srcModifiedFile, tmpdir + copyFile);
+@test:Config {dependsOn: [testCopyFileToExistingFileReplaceFalse]}
+function testCopyFileToExistingFileReplaceTrue() {
+    MetaData|error srcMetadata = getMetaData(srcModifiedFile);
+    if srcMetadata is MetaData {
+        srcModifiedFileLength = srcMetadata.size;
+    } else {
+        test:assertFail("Error retrieving source file size!");
+    }
+    error? copyResult = copy(srcModifiedFile, tmpdir + copyFile, REPLACE_EXISTING);
     if copyResult is error {
         test:assertFail("File not copied!");
     } else {
         MetaData|error metadata = getMetaData(tmpdir + copyFile);
         if metadata is MetaData {
             int destFileLength = metadata.size;
-            test:assertEquals(destFileLength, srcFileLength, "File size mismatch!");
-            test:assertNotEquals(destFileLength, srcModifiedFileLength);
+            test:assertEquals(destFileLength, srcModifiedFileLength, "File size mismatch!");
+            test:assertNotEquals(destFileLength, srcFileLength);
+            error? removeResult = remove(tmpdir + copyFile);
+            if removeResult is error {
+                test:assertFail("Error removing test resource!");
+            }
         } else {
             test:assertFail("Error retrieving destination file size!");
         }
     }
 }
 
-@test:Config {dependsOn: [testCopyFileReplaceFalse]}
-function testCopyFileReplaceTrue() {
-    error? copyResult = copy(srcModifiedFile, tmpdir + copyFile, REPLACE_EXISTING);
+@test:Config {dependsOn: [testCopyFileToExistingFileReplaceTrue]}
+function testCopyFileToNonExistentFileReplaceTrue() {
+    error? copyResult = copy(srcFile, tmpdir + copyFile, REPLACE_EXISTING);
     if copyResult is error {
         test:assertFail("File not copied!");
     } else {
         MetaData|error metadata = getMetaData(tmpdir + copyFile);
         if metadata is MetaData {
             int destFileLength = metadata.size;
-            test:assertEquals(destFileLength, srcModifiedFileLength, "File size mismatch!");
-            test:assertNotEquals(destFileLength, srcFileLength);
+            test:assertEquals(destFileLength, srcFileLength, "File size mismatch!");
             error? removeResult = remove(tmpdir + copyFile);
             if removeResult is error {
                 test:assertFail("Error removing test resource!");

native/src/main/java/io/ballerina/stdlib/file/nativeimpl/Utils.java

@@ -299,6 +299,9 @@ public static Object copy(BString sourcePath, BString destinationPath, BString..
         } catch (NoSuchFileException ex) {
             return FileUtils.getBallerinaError(FileConstants.FILE_NOT_FOUND_ERROR,
                     "The target directory does not exist: " + ex.getMessage());
+        } catch (FileAlreadyExistsException ex) {
+            return FileUtils.getBallerinaError(FileConstants.INVALID_OPERATION_ERROR,
+                    "The target file already exists: " + ex.getMessage());
         } catch (IOException ex) {
             return FileUtils.getBallerinaError(FileConstants.FILE_SYSTEM_ERROR,
                     "An error occurred when copying the file/s: " + ex.getMessage());
@@ -335,7 +338,7 @@ public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IO
             Path newFile = target.resolve(source.relativize(file));
             try {
                 Files.copy(file, newFile, copyOptions);
-            } catch (NoSuchFileException e) {
+            } catch (IOException e) {
                 throw e;
             } catch (Exception e) {
                 log.debug(e.getMessage());