feat: add filetype module (#1500)

* feat: add filetype module

* ci(test): filetype detection for notebook cells

runtime/lua/vscode-neovim.lua

@@ -3,6 +3,7 @@ local defaults = require("vscode-neovim.defaults")
 local cursor = require("vscode-neovim.cursor")
 
 require("vscode-neovim.highlight")
+require("vscode-neovim.filetype")
 
 local M = {}
 

runtime/lua/vscode-neovim/filetype.lua

@@ -0,0 +1,14 @@
+vim.filetype.add({
+  pattern = {
+    -- To ensure that the user's fallback pattern is not overridden.
+    [".*.*.*"] = {
+      priority = -math.huge,
+      function(_, bufnr)
+        local name = vim.api.nvim_buf_get_name(bufnr)
+        if name:match("vscode%-notebook%-cell") then
+          return "python"
+        end
+      end,
+    },
+  },
+})

src/test/suite/vscode-integration-specific.test.ts

@@ -425,6 +425,20 @@ describe("VSCode integration specific stuff", () => {
         assert.strictEqual("typescript", type);
     });
 
+    it("Filetype detection (jupyter notebook)", async function () {
+        this.retries(2);
+
+        const note = await vscode.workspace.openNotebookDocument(
+            vscode.Uri.file(path.join(__dirname, "../../../test_fixtures/window-changed.ipynb")),
+        );
+        await vscode.window.showNotebookDocument(note, { viewColumn: vscode.ViewColumn.One });
+        await wait(1000);
+
+        const buf = await client.buffer;
+        const type = await client.request("nvim_buf_get_option", [buf.id, "filetype"]);
+        assert.strictEqual("python", type);
+    });
+
     it("Next search result works", async () => {
         await openTextDocument(path.join(__dirname, "../../../test_fixtures/incsearch-scroll.ts"));