feat(java): add kmp-lsp as an alternative language server (#1891)

crates/ide-tools/src/platform.rs

@@ -151,6 +151,36 @@ mod tests {
         assert_eq!(select_asset(&names, rules, WIN), Some(names[4]));
     }
 
+    #[test]
+    fn kmp_lsp_assets_include_the_native_jar_indexer() {
+        let names = [
+            "kmp-lsp-darwin-aarch64.gz",
+            "kmp-lsp-darwin-aarch64.tar.gz",
+            "kmp-lsp-darwin-x86_64.tar.gz",
+            "kmp-lsp-linux-aarch64.tar.gz",
+            "kmp-lsp-linux-x86_64.tar.gz",
+            "kmp-lsp-windows-x86_64.zip",
+            "kmp-lsp-windows-aarch64.zip",
+            "kmp-lsp-v0.27.0.vsix",
+            "kmp-lsp-win32-x64-v0.27.0.vsix",
+            "kmp-lsp-win32-arm64-v0.27.0.vsix",
+        ];
+        let rules = crate::registry::find("kmp-lsp").unwrap().asset_rules();
+        for (os, arch, expected) in [
+            (Os::Mac, Arch::Arm64, names[1]),
+            (Os::Mac, Arch::X64, names[2]),
+            (Os::Linux, Arch::Arm64, names[3]),
+            (Os::Linux, Arch::X64, names[4]),
+            (Os::Windows, Arch::X64, names[8]),
+            (Os::Windows, Arch::Arm64, names[9]),
+        ] {
+            assert_eq!(select_asset(&names, rules, Platform { os, arch }), Some(expected));
+        }
+        // The plain gzip, Windows zip and universal VSIX omit the sidecar or server.
+        assert_eq!(select_asset(&[names[0]], rules, MAC_ARM), None);
+        assert_eq!(select_asset(&names[5..8], rules, WIN), None);
+    }
+
     #[test]
     fn rosetta_fallback_and_missing() {
         let names = ["zls-x86_64-macos.tar.xz", "zls-x86_64-linux.tar.xz", "zls-x86_64-windows.zip"];

crates/ide-tools/src/registry.rs

@@ -618,6 +618,30 @@ pub static TOOLS: &[ToolSpec] = &[
         homepage: "https://github.com/eclipse-jdtls/eclipse.jdt.ls",
         needs: &[],
     },
+    ToolSpec {
+        name: "kmp-lsp",
+        display: "kmp-lsp",
+        kind: LanguageServer,
+        commands: &["kmp-lsp"],
+        method: Method::Release {
+            source: ReleaseSource::GitHub { repo: "Hessesian/kmp-lsp" },
+            // These distributions include the native JAR indexer next to the server.
+            // The single-binary .gz and Windows .zip assets do not.
+            assets: &[
+                rule(Mac, Arm64, "kmp-lsp-darwin-aarch64.tar.gz"),
+                rule(Mac, X64, "kmp-lsp-darwin-x86_64.tar.gz"),
+                rule(Linux, Arm64, "kmp-lsp-linux-aarch64.tar.gz"),
+                rule(Linux, X64, "kmp-lsp-linux-x86_64.tar.gz"),
+                rule(Windows, Arm64, "kmp-lsp-win32-arm64-*.vsix"),
+                rule(Windows, X64, "kmp-lsp-win32-x64-*.vsix"),
+            ],
+            locate: &["kmp-lsp"],
+        },
+        fallback: None,
+        version: ver("kmp-lsp"),
+        homepage: "https://github.com/Hessesian/kmp-lsp",
+        needs: &[],
+    },
     ToolSpec {
         name: "java-debug",
         display: "Java Debugger (Microsoft java-debug)",

crates/ide-tools/src/tests.rs

@@ -170,6 +170,10 @@ fn interchangeable_servers_list_their_alternatives() {
         assert_eq!(find(&list, name).alternatives, python);
     }
     assert_eq!(find(&list, "vtsls").alternatives, ["vtsls", "typescript-language-server"]);
+    for name in ["jdtls", "kmp-lsp"] {
+        assert_eq!(find(&list, name).alternatives, ["jdtls", "kmp-lsp"]);
+        assert_eq!(find(&list, name).languages, ["Java"]);
+    }
     // A regular server after a fallback starts no group with it.
     assert!(find(&list, "angular-language-server").alternatives.is_empty());
     assert!(find(&list, "ruff").alternatives.is_empty());