feat: add experimental support for Ruff language server #5345

packages/opencode/src/flag/flag.ts

@@ -37,6 +37,7 @@ export namespace Flag {
   export const OPENCODE_EXPERIMENTAL_OUTPUT_TOKEN_MAX = number("OPENCODE_EXPERIMENTAL_OUTPUT_TOKEN_MAX")
   export const OPENCODE_EXPERIMENTAL_OXFMT = OPENCODE_EXPERIMENTAL || truthy("OPENCODE_EXPERIMENTAL_OXFMT")
   export const OPENCODE_EXPERIMENTAL_LSP_TY = truthy("OPENCODE_EXPERIMENTAL_LSP_TY")
+  export const OPENCODE_EXPERIMENTAL_LSP_RUFF = truthy("OPENCODE_EXPERIMENTAL_LSP_RUFF")
   export const OPENCODE_EXPERIMENTAL_LSP_TOOL = OPENCODE_EXPERIMENTAL || truthy("OPENCODE_EXPERIMENTAL_LSP_TOOL")
   export const OPENCODE_EXPERIMENTAL_PLAN_MODE = OPENCODE_EXPERIMENTAL || truthy("OPENCODE_EXPERIMENTAL_PLAN_MODE")
 

packages/opencode/src/lsp/index.ts

@@ -62,17 +62,26 @@ export namespace LSP {
   export type DocumentSymbol = z.infer<typeof DocumentSymbol>
 
   const filterExperimentalServers = (servers: Record<string, LSPServer.Info>) => {
+    const disable = (id: string, reason?: string) => {
+      if (!servers[id]) return
+      if (reason) log.info(reason)
+      delete servers[id]
+    }
+
     if (Flag.OPENCODE_EXPERIMENTAL_LSP_TY) {
-      // If experimental flag is enabled, disable pyright
-      if (servers["pyright"]) {
-        log.info("LSP server pyright is disabled because OPENCODE_EXPERIMENTAL_LSP_TY is enabled")
-        delete servers["pyright"]
-      }
-    } else {
-      // If experimental flag is disabled, disable ty
-      if (servers["ty"]) {
-        delete servers["ty"]
-      }
+      disable("pyright", "LSP server pyright is disabled because OPENCODE_EXPERIMENTAL_LSP_TY is enabled")
+    }
+
+    if (!Flag.OPENCODE_EXPERIMENTAL_LSP_TY) {
+      disable("ty")
+    }
+
+    if (Flag.OPENCODE_EXPERIMENTAL_LSP_RUFF) {
+      disable("pyright", "LSP server pyright is disabled because OPENCODE_EXPERIMENTAL_LSP_RUFF is enabled")
+    }
+
+    if (!Flag.OPENCODE_EXPERIMENTAL_LSP_RUFF) {
+      disable("ruff")
     }
   }
 

packages/opencode/src/lsp/server.ts

@@ -502,6 +502,57 @@ export namespace LSPServer {
     },
   }
 
+  export const Ruff: Info = {
+    id: "ruff",
+    extensions: [".py", ".pyi"],
+    root: NearestRoot([
+      "pyproject.toml",
+      "ruff.toml",
+      ".ruff.toml",
+      "setup.py",
+      "setup.cfg",
+      "requirements.txt",
+      "Pipfile",
+    ]),
+    async spawn(root) {
+      if (!Flag.OPENCODE_EXPERIMENTAL_LSP_RUFF) {
+        return undefined
+      }
+
+      const venvs = [process.env["VIRTUAL_ENV"], path.join(root, ".venv"), path.join(root, "venv")].filter(
+        (p): p is string => p !== undefined,
+      )
+
+      const binary = await (async () => {
+        const direct = Bun.which("ruff")
+        if (direct) return direct
+
+        for (const venv of venvs) {
+          const windows = process.platform === "win32"
+          const candidate = windows ? path.join(venv, "Scripts", "ruff.exe") : path.join(venv, "bin", "ruff")
+          if (await Bun.file(candidate).exists()) {
+            return candidate
+          }
+        }
+
+        return undefined
+      })()
+
+      if (!binary) {
+        log.error("ruff not found, please install ruff first")
+        return
+      }
+
+      const proc = spawn(binary, ["server"], {
+        cwd: root,
+      })
+
+      return {
+        process: proc,
+      }
+    },
+  }
+
   export const Pyright: Info = {
     id: "pyright",
     extensions: [".py", ".pyi"],