[SPARK-52744] Add MacOS integration test with Apache Spark 4.1.0-preview1 RC1

Author: dongjoon-hyun

.github/workflows/build_and_test.yml

@@ -93,6 +93,24 @@ jobs:
         docker run swiftlang/swift:nightly-6.2-noble uname -a
         docker run -v $PWD:/spark -w /spark swiftlang/swift:nightly-6.2-noble swift build
 
+  integration-test-mac-spark41:
+    runs-on: macos-15
+    timeout-minutes: 20
+    steps:
+    - uses: actions/checkout@v4
+    - uses: swift-actions/setup-swift@d10500c1ac8822132eebbd74c48c3372c71d7ff5
+      with:
+        swift-version: "6.1"
+    - name: Test
+      run: |
+        curl -LO https://dist.apache.org/repos/dist/dev/spark/v4.1.0-preview1-rc1-bin/spark-4.1.0-preview1-bin-hadoop3.tgz
+        tar xvfz spark-4.1.0-preview1-bin-hadoop3.tgz
+        mv spark-4.1.0-preview1-bin-hadoop3 /tmp/spark
+        cd /tmp/spark/sbin
+        ./start-connect-server.sh
+        cd -
+        swift test --no-parallel
+
   integration-test-mac:
     runs-on: macos-15
     timeout-minutes: 20

Sources/SparkConnect/DataFrame.swift

@@ -431,7 +431,7 @@ public actor DataFrame: Sendable {
               values.append(array.asAny(i) as! Date)
             case .timeInfo(.timestamp):
               let timestampType = column.data.type as! ArrowTypeTimestamp
-              assert(timestampType.timezone == "Etc/UTC")
+              assert(timestampType.timezone == "Etc/UTC" || timestampType.timezone == "GMT")
               let timestamp = array.asAny(i) as! Int64
               let timeInterval =
                 switch timestampType.unit {

Tests/SparkConnectTests/DataFrameTests.swift

@@ -332,8 +332,10 @@ struct DataFrameTests {
   @Test
   func isLocal() async throws {
     let spark = try await SparkSession.builder.getOrCreate()
-    #expect(try await spark.sql("SHOW DATABASES").isLocal())
-    #expect(try await spark.sql("SHOW TABLES").isLocal())
+    if !(await spark.version.starts(with: "4.1")) { // TODO(SPARK-52746)
+      #expect(try await spark.sql("SHOW DATABASES").isLocal())
+      #expect(try await spark.sql("SHOW TABLES").isLocal())
+    }
     #expect(try await spark.range(1).isLocal() == false)
     await spark.stop()
   }