Make java and neotest config portable

jdtls hardcoded /Library/Java/JavaVirtualMachines paths, which resolve to
nothing off macOS; discover JDKs across the macOS, Linux and sdkman roots
instead and only declare runtimes that exist. neotest-mocha passed `docker exec
-it`, which hangs without a TTY, and hardcoded the container name.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

lua/plugins/java.lua

@@ -1,15 +1,50 @@
+local function first_jdk(candidates)
+  for _, path in ipairs(candidates) do
+    if vim.fn.executable(path .. "/bin/java") == 1 then
+      return path
+    end
+  end
+end
+
+local function find_jdk(patterns)
+  local roots = {
+    "/Library/Java/JavaVirtualMachines/%s/Contents/Home",
+    "/usr/lib/jvm/%s",
+    vim.fn.expand("~") .. "/.sdkman/candidates/java/%s",
+  }
+  local candidates = {}
+  for _, pattern in ipairs(patterns) do
+    for _, root in ipairs(roots) do
+      for _, path in ipairs(vim.fn.glob(root:format(pattern), true, true)) do
+        candidates[#candidates + 1] = path
+      end
+    end
+  end
+  return first_jdk(candidates)
+end
+
 return {
   {
     "mfussenegger/nvim-jdtls",
     opts = function(_, opts)
-      local corretto8 = "/Library/Java/JavaVirtualMachines/amazon-corretto-8.jdk/Contents/Home"
-      local temurin21 = "/Library/Java/JavaVirtualMachines/temurin-21.jdk/Contents/Home"
+      local jdk8 = find_jdk({ "*corretto-8*", "*corretto*1.8*", "*-8-*", "*java-8*", "*1.8*" })
+      local jdk21 = find_jdk({ "*temurin-21*", "*-21-*", "*java-21*", "*21*" })
 
-      opts.cmd = opts.cmd or {}
-      table.insert(opts.cmd, "--java-executable")
-      table.insert(opts.cmd, temurin21 .. "/bin/java")
+      if jdk21 then
+        opts.cmd = opts.cmd or {}
+        table.insert(opts.cmd, "--java-executable")
+        table.insert(opts.cmd, jdk21 .. "/bin/java")
+      end
 
-      local project_jdk = vim.env.JAVA_HOME or temurin21
+      local runtimes = {}
+      if jdk8 then
+        table.insert(runtimes, { name = "JavaSE-1.8", path = jdk8 })
+      end
+      if jdk21 then
+        table.insert(runtimes, { name = "JavaSE-21", path = jdk21 })
+      end
+
+      local project_jdk = vim.env.JAVA_HOME or jdk21
 
       opts.settings = vim.tbl_deep_extend("force", opts.settings or {}, {
         java = {
@@ -19,10 +54,7 @@ return {
             },
           },
           configuration = {
-            runtimes = {
-              { name = "JavaSE-1.8", path = corretto8 },
-              { name = "JavaSE-21", path = temurin21 },
-            },
+            runtimes = runtimes,
           },
         },
       })

lua/plugins/neotest.lua

@@ -7,7 +7,7 @@ return {
     return {
       adapters = {
         ["neotest-mocha"] = {
-          command = "docker exec -it api-sandbox npm run test:integration",
+          command = "docker exec " .. (vim.env.NEOTEST_MOCHA_CONTAINER or "api-sandbox") .. " npm run test:integration",
           command_args = function(context)
             -- The context contains:
             --   results_path: The file that json results are written to