Separate system modules tests into their own file

java_test.go is getting too big.

Bug: 182402568
Test: m nothing
Change-Id: I9c3818f1d747a230fcb66687319a3a14d557a57c
diff --git a/java/system_modules_test.go b/java/system_modules_test.go
new file mode 100644
index 0000000..23d6c7b
--- /dev/null
+++ b/java/system_modules_test.go
@@ -0,0 +1,84 @@
+// Copyright 2021 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package java
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestJavaSystemModules(t *testing.T) {
+	ctx, _ := testJava(t, `
+		java_system_modules {
+			name: "system-modules",
+			libs: ["system-module1", "system-module2"],
+		}
+		java_library {
+			name: "system-module1",
+			srcs: ["a.java"],
+			sdk_version: "none",
+			system_modules: "none",
+		}
+		java_library {
+			name: "system-module2",
+			srcs: ["b.java"],
+			sdk_version: "none",
+			system_modules: "none",
+		}
+		`)
+
+	// check the existence of the module
+	systemModules := ctx.ModuleForTests("system-modules", "android_common")
+
+	cmd := systemModules.Rule("jarsTosystemModules")
+
+	// make sure the command compiles against the supplied modules.
+	for _, module := range []string{"system-module1.jar", "system-module2.jar"} {
+		if !strings.Contains(cmd.Args["classpath"], module) {
+			t.Errorf("system modules classpath %v does not contain %q", cmd.Args["classpath"],
+				module)
+		}
+	}
+}
+
+func TestJavaSystemModulesImport(t *testing.T) {
+	ctx, _ := testJava(t, `
+		java_system_modules_import {
+			name: "system-modules",
+			libs: ["system-module1", "system-module2"],
+		}
+		java_import {
+			name: "system-module1",
+			jars: ["a.jar"],
+		}
+		java_import {
+			name: "system-module2",
+			jars: ["b.jar"],
+		}
+		`)
+
+	// check the existence of the module
+	systemModules := ctx.ModuleForTests("system-modules", "android_common")
+
+	cmd := systemModules.Rule("jarsTosystemModules")
+
+	// make sure the command compiles against the supplied modules.
+	for _, module := range []string{"system-module1.jar", "system-module2.jar"} {
+		if !strings.Contains(cmd.Args["classpath"], module) {
+			t.Errorf("system modules classpath %v does not contain %q", cmd.Args["classpath"],
+				module)
+		}
+	}
+}