SNOW-1708304: Download stream from git repository

src/main/java/net/snowflake/client/jdbc/SnowflakeFileTransferAgent.java

@@ -1662,14 +1662,34 @@ public InputStream downloadStream(String fileName) throws SnowflakeSQLException
 
     remoteLocation remoteLocation = extractLocationAndPath(stageInfo.getLocation());
 
-    String stageFilePath = fileName;
+    // when downloading files as stream there should be only one file in source files
+    String sourceLocation =
+        sourceFiles.stream()
+            .findFirst()
+            .orElseThrow(
+                () ->
+                    new SnowflakeSQLException(
+                        queryID,
+                        SqlState.NO_DATA,
+                        ErrorCode.FILE_NOT_FOUND.getMessageCode(),
+                        session,
+                        "File not found: " + fileName));
+
+    String stageFilePath;
+    if (fileName.equals(sourceLocation)) {
+      stageFilePath = fileName;
+    } else {
+      // filename may be different from source location e.g. in git repositories
+      logger.debug("Changing file to download location from {} to {}", fileName, sourceLocation);
+      stageFilePath = sourceLocation;
+    }
 
     if (!remoteLocation.path.isEmpty()) {
-      stageFilePath = SnowflakeUtil.concatFilePathNames(remoteLocation.path, fileName, "/");
+      stageFilePath = SnowflakeUtil.concatFilePathNames(remoteLocation.path, sourceLocation, "/");
     }
 
-    RemoteStoreFileEncryptionMaterial encMat = srcFileToEncMat.get(fileName);
-    String presignedUrl = srcFileToPresignedUrl.get(fileName);
+    RemoteStoreFileEncryptionMaterial encMat = srcFileToEncMat.get(sourceLocation);
+    String presignedUrl = srcFileToPresignedUrl.get(sourceLocation);
 
     return storageFactory
         .createClient(stageInfo, parallel, encMat, session)

src/test/java/net/snowflake/client/jdbc/GitRepositoryDownloadLatestIT.java

@@ -0,0 +1,81 @@
+package net.snowflake.client.jdbc;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.List;
+import net.snowflake.client.category.TestCategoryOthers;
+import org.apache.commons.io.IOUtils;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category(TestCategoryOthers.class)
+public class GitRepositoryDownloadLatestIT extends BaseJDBCWithSharedConnectionIT {
+  @Test
+  public void shouldDownloadFileAndStreamFromGitRepository() throws Exception {
+    prepareJdbcRepoInSnowflake();
+
+    String stageName =
+        String.format("@%s.%s.JDBC", connection.getCatalog(), connection.getSchema());
+    String fileName = ".pre-commit-config.yaml";
+    String filePathInGitRepo = "branches/master/" + fileName;
+
+    List<String> fetchedFileContent = getContentFromFile(stageName, filePathInGitRepo, fileName);
+
+    List<String> fetchedStreamContent = getContentFromStream(stageName, filePathInGitRepo);
+
+    assertFalse("File content cannot be empty", fetchedFileContent.isEmpty());
+    assertFalse("Stream content cannot be empty", fetchedStreamContent.isEmpty());
+    assertEquals(fetchedFileContent, fetchedStreamContent);
+  }
+
+  private static void prepareJdbcRepoInSnowflake() throws SQLException {
+    try (Statement statement = connection.createStatement()) {
+      statement.execute(
+          "CREATE OR REPLACE API INTEGRATION gh_integration\n"
+              + "  API_PROVIDER = git_https_api\n"
+              + "  API_ALLOWED_PREFIXES = ('https://github.com/snowflakedb/snowflake-jdbc.git')\n"
+              + "  ENABLED = TRUE;");
+      statement.execute(
+          "CREATE OR REPLACE GIT REPOSITORY jdbc\n"
+              + "ORIGIN = 'https://github.com/snowflakedb/snowflake-jdbc.git'\n"
+              + "API_INTEGRATION = gh_integration;");
+    }
+  }
+
+  private static List<String> getContentFromFile(
+      String stageName, String filePathInGitRepo, String fileName)
+      throws IOException, SQLException {
+    Path tempDir = Files.createTempDirectory("git");
+    String stagePath = stageName + "/" + filePathInGitRepo;
+    Path downloadedFile = tempDir.resolve(fileName);
+    String command = String.format("GET '%s' '%s'", stagePath, tempDir.toUri());
+
+    try (Statement statement = connection.createStatement();
+        ResultSet rs = statement.executeQuery(command); ) {
+      // then
+      assertTrue("has result", rs.next());
+      return Files.readAllLines(downloadedFile);
+    } finally {
+      Files.delete(downloadedFile);
+      Files.delete(tempDir);
+    }
+  }
+
+  private static List<String> getContentFromStream(String stageName, String filePathInGitRepo)
+      throws SQLException, IOException {
+    SnowflakeConnection unwrap = connection.unwrap(SnowflakeConnection.class);
+    try (InputStream inputStream = unwrap.downloadStream(stageName, filePathInGitRepo, false)) {
+      return IOUtils.readLines(inputStream, StandardCharsets.UTF_8);
+    }
+  }
+}