add test binary tests

databuild/test/BUILD.bazel

@@ -5,3 +5,10 @@ rust_binary(
     srcs = ["test_job_helper.rs"],
     visibility = ["//visibility:public"],
 )
+
+sh_test(
+    name = "test_job_helper_test",
+    srcs = ["test_job_helper_test.sh"],
+    args = ["$(location :test_job_helper)"],
+    data = [":test_job_helper"],
+)

databuild/test/test_job_helper_test.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+set -e
+
+HELPER="$1"
+
+# Test 1: Default behavior - exit code 0, default stdout
+OUTPUT=$("$HELPER")
+if [ "$OUTPUT" != "test executed" ]; then
+    echo "Test 1 failed: Expected 'test executed', got '$OUTPUT'"
+    exit 1
+fi
+echo "Test 1 passed: Default stdout"
+
+# Test 2: Custom exit code
+DATABUILD_TEST_EXIT_CODE=42 "$HELPER" || EXIT_CODE=$?
+if [ "$EXIT_CODE" != "42" ]; then
+    echo "Test 2 failed: Expected exit code 42, got $EXIT_CODE"
+    exit 1
+fi
+echo "Test 2 passed: Custom exit code"
+
+# Test 3: Custom stdout message
+OUTPUT=$(DATABUILD_TEST_STDOUT="custom message" "$HELPER")
+if [ "$OUTPUT" != "custom message" ]; then
+    echo "Test 3 failed: Expected 'custom message', got '$OUTPUT'"
+    exit 1
+fi
+echo "Test 3 passed: Custom stdout"
+
+# Test 4: Write to file
+TEMP_FILE=$(mktemp)
+DATABUILD_TEST_OUTPUT_FILE="$TEMP_FILE" DATABUILD_TEST_FILE_CONTENT="hello world" "$HELPER" > /dev/null
+if [ ! -f "$TEMP_FILE" ]; then
+    echo "Test 4 failed: Output file not created"
+    exit 1
+fi
+CONTENT=$(cat "$TEMP_FILE")
+if [ "$CONTENT" != "hello world" ]; then
+    echo "Test 4 failed: Expected 'hello world' in file, got '$CONTENT'"
+    rm "$TEMP_FILE"
+    exit 1
+fi
+rm "$TEMP_FILE"
+echo "Test 4 passed: Write to file"
+
+echo "All tests passed!"