Fix kernel registration on windows

Author: DonJayamanne

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Change Log
 
+### 1.1.0
+
+- Fix kernel registration on Windows.
 ## [1.0.0]
 
 - Initial release

README.md

@@ -24,6 +24,9 @@ This extension will automatically install the necessary dependencies required to
 
 ## Release Notes
 
+### 1.1.0
+
+- Fix kernel registration on Windows.
 ### 1.0.0
 
-Initial release
+- Initial release

package.json

@@ -3,7 +3,7 @@
 	"publisher": "donjayamanne",
 	"displayName": "TypeScript Notebooks",
     "description": "TypeScript with Jupyter Notebooks",
-	"version": "1.0.0",
+	"version": "1.1.0",
 	"engines": {
 		"vscode": "^1.53.0"
 	},

src/extension.ts

@@ -18,8 +18,7 @@ export async function activate(context: ExtensionContext) {
     installKernelSpec(),
     registerWithJupyter(),
     optIntoNativeNotebooks(),
-    configureEditor(),
-    installKernelSpec(),
+    configureEditor()
   ]).catch(noop);
   registerCommands(context, outputChannel);
 }

src/kernel.ts

@@ -2,17 +2,18 @@ import * as path from "path";
 import { homedir } from "os";
 import * as fs from "fs-extra";
 import { logMessage } from "./logger";
+import { format } from "util";
 
 const winJupyterPath = path.join("AppData", "Roaming", "jupyter", "kernels");
 const linuxJupyterPath = path.join(".local", "share", "jupyter", "kernels");
 const macJupyterPath = path.join("Library", "Jupyter", "kernels");
-
-function getKernelsDir(platform: string = process.platform) {
-  if (/^win/.test(platform)) {
+const isWindows = /^win/.test(process.platform);
+function getKernelsDir() {
+  if (isWindows) {
     return winJupyterPath;
-  } else if (/^darwin/.test(platform)) {
+  } else if (/^darwin/.test(process.platform)) {
     return macJupyterPath;
-  } else if (/^linux/.test(platform)) {
+  } else if (/^linux/.test(process.platform)) {
     return linuxJupyterPath;
   } else {
     throw new Error("Unable to determine the OS");
@@ -30,19 +31,43 @@ async function ensureKernelsDirectory() {
   await fs.ensureDir(kernelsDir);
 }
 
+const tslabExecutable = isWindows ? "tslab.cmd" : "tslab";
+
 const kernelSpec = {
-  argv: ["tslab", "kernel", "--config-path", "{connection_file}"],
+  argv: [tslabExecutable, "kernel", "--config-path", "{connection_file}"],
   // eslint-disable-next-line @typescript-eslint/naming-convention
   display_name: "TypeScript",
   language: "typescript",
 };
 const kernelSpecName = "typescript";
 
+export async function updateKernelSpec(kernelSpecFile: string) {
+  if (!isWindows) {
+    return;
+  }
+  try {
+    const contents: typeof kernelSpec = await fs.readJSON(kernelSpecFile, {
+      encoding: "utf8",
+    });
+    if (contents.argv[0] === tslabExecutable) {
+      return;
+    }
+    await fs.writeFile(kernelSpecFile, JSON.stringify(kernelSpec), {
+      flag: "w",
+    });
+    logMessage(`Existing KernelSpec updated ${kernelSpecFile}`);
+  } catch (ex) {
+    logMessage(`Failed to update kernel.json ${format(ex)}`);
+  }
+  return;
+}
+
 export async function installKernelSpec() {
   await ensureKernelsDirectory();
   const kernelSpecDirectory = path.join(kernelsDir, kernelSpecName);
   const kernelSpecFile = path.join(kernelSpecDirectory, "kernel.json");
   if (await fs.pathExists(kernelSpecFile)) {
+    updateKernelSpec(kernelSpecFile);
     logMessage(`KernelSpec already exists ${kernelSpecFile}`);
     return;
   }