feat: add test suite for java version detector.

Author: epicbigcat

src/util/java.cpp

@@ -7,21 +7,16 @@
 
 namespace allay_launcher::util::java {
 
-Version installed_version() {
+Version installed_version(std::string_view cmdoutput) {
     using namespace string;
 
-    // Do not use "java --version", which is not supported on java-1.8
-    // The output of this command will be written into error stream
-    // so we need to add the suffix "2>&1" to redirect the output
-    auto output = os::execute("java -version 2>&1");
-
-    auto lines             = split_nocopy(output, "\n");
+    auto lines             = split_nocopy(cmdoutput, "\n");
     auto first_line_tokens = split_nocopy(lines.at(0), " ");
 
     // openjdk version "21.0.4" 2024-07-16
     //                          ^ (optional)
     if (first_line_tokens.size() < 3) {
-        throw ParserException(output, "unable to parse java version.");
+        throw ParserException(cmdoutput, "unable to parse java version.");
     }
 
     auto version_string = first_line_tokens.at(2);
@@ -40,6 +35,13 @@ Version installed_version() {
     }
 }
 
+Version installed_version() {
+    // Do not use "java --version", which is not supported on java-1.8
+    // The output of this command will be written into error stream
+    // so we need to add the suffix "2>&1" to redirect the output
+    return installed_version(os::execute("java -version 2>&1"));
+}
+
 bool check_java() try {
     bool is_java_ok = false;
 

src/util/java.h

@@ -4,6 +4,8 @@
 
 namespace allay_launcher::util::java {
 
+Version installed_version(std::string_view cmdoutput);
+
 /* @Throwable ParserException
  * @Throwable CommandExecutionException
  */

tests/util/java.cpp

@@ -0,0 +1,87 @@
+#include "test_suite.h" // IWYU pragma: keep
+
+#include "util/java.h"
+
+using namespace util::java;
+
+TEST(TestJavaVersionDetection, Java_8) {
+    auto version  = installed_version(R"(java version "1.8.0_421"
+Java(TM) SE Runtime Environment (build 1.8.0_421-b08)
+Java HotSpot(TM) 64-Bit Server VM (build 25.421-b08, mixed mode)
+)");
+    auto expected = Version{1, 8, 0};
+    EXPECT_EQ(version, expected);
+}
+
+TEST(TestJavaVersionDetection, OpenJDK_11) {
+    auto version  = installed_version(R"(openjdk version "11.0.23" 2024-04-16
+OpenJDK Runtime Environment (build 11.0.23+9-LTS)
+OpenJDK 64-Bit Server VM (build 11.0.23+9-LTS, mixed mode)
+)");
+    auto expected = Version{11, 0, 23};
+    EXPECT_EQ(version, expected);
+}
+
+TEST(TestJavaVersionDetection, OpenJDK_17) {
+    auto version  = installed_version(R"(openjdk version "17.0.11" 2024-04-16
+OpenJDK Runtime Environment (build 17.0.11+9-LTS)
+OpenJDK 64-Bit Server VM (build 17.0.11+9-LTS, mixed mode, sharing)
+)");
+    auto expected = Version{17, 0, 11};
+    EXPECT_EQ(version, expected);
+}
+
+TEST(TestJavaVersionDetection, OpenJDK_21) {
+    auto version  = installed_version(R"(openjdk version "21.0.3" 2024-04-16 LTS
+OpenJDK Runtime Environment (build 21.0.3+9-LTS)
+OpenJDK 64-Bit Server VM (build 21.0.3+9-LTS, mixed mode, sharing)
+)");
+    auto expected = Version{21, 0, 3};
+    EXPECT_EQ(version, expected);
+}
+
+TEST(TestJavaVersionDetection, OpenJDK_23) {
+    auto version  = installed_version(R"(openjdk version "23"
+2024-09-17 OpenJDK Runtime Environment (build 23+37-1231)
+OpenJDK 64-Bit Server VM (build 23+37-1231, mixed mode, sharing)
+)");
+    auto expected = Version{23, 0, 0};
+    EXPECT_EQ(version, expected);
+}
+
+TEST(TestJavaVersionDetection, OpenJDK_25_EA) {
+    auto version  = installed_version(R"(openjdk version "25-ea" 2026-03-17
+OpenJDK Runtime Environment (build 25-ea+3-19)
+OpenJDK 64-Bit Server VM (build 25-ea+3-19, mixed mode, sharing)
+)");
+    auto expected = Version{25, 0, 0};
+    EXPECT_EQ(version, expected);
+}
+
+TEST(TestJavaVersionDetection, OpenJDK_GraalVM_11) {
+    auto version  = installed_version(R"(openjdk version "11.0.16" 2022-07-19
+OpenJDK Runtime Environment GraalVM EE 22.2.0 (build 11.0.16+8-jvmci-22.2-b08)
+OpenJDK 64-Bit Server VM GraalVM EE 22.2.0 (build 11.0.16+8-jvmci-22.2-b08, mixed mode, sharing)
+
+)");
+    auto expected = Version{11, 0, 16};
+    EXPECT_EQ(version, expected);
+}
+
+TEST(TestJavaVersionDetection, GraalVM_21) {
+    auto version  = installed_version(R"(java version "21.0.8" 2025-07-15 LTS
+Java(TM) SE Runtime Environment Oracle GraalVM 21.0.8+12.1 (build 21.0.8+12-LTS-jvmci-23.1-b72)
+Java HotSpot(TM) 64-Bit Server VM Oracle GraalVM 21.0.8+12.1 (build 21.0.8+12-LTS-jvmci-23.1-b72, mixed mode, sharing)
+)");
+    auto expected = Version{21, 0, 8};
+    EXPECT_EQ(version, expected);
+}
+
+TEST(TestJavaVersionDetection, GraalVM_24) {
+    auto version  = installed_version(R"(java version "24.0.2" 2025-07-15
+Java(TM) SE Runtime Environment Oracle GraalVM 24.0.2+11.1 (build 24.0.2+11-jvmci-b01)
+Java HotSpot(TM) 64-Bit Server VM Oracle GraalVM 24.0.2+11.1 (build 24.0.2+11-jvmci-b01, mixed mode, sharing)
+)");
+    auto expected = Version{24, 0, 2};
+    EXPECT_EQ(version, expected);
+}