feat: make pixi-kernel work independently of kernel provisioner

This is specially important when trying to use it in VSCode when
`jupyter-client` isn't used to launch a kernel.

.github/workflows/ci.yml

@@ -67,3 +67,15 @@ jobs:
           run-install: false
       - name: Run code quality checks
         run: pixi run --locked --environment ruff lint
+  type-check:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+      - name: Install Pixi ${{ env.pixi-version }}
+        uses: prefix-dev/setup-pixi@v0.5.1
+        with:
+          pixi-version: v${{ env.pixi-version }}
+          run-install: false
+      - name: Run type checks
+        run: pixi run --locked --environment mypy type-check

.gitignore

@@ -12,6 +12,9 @@ dist
 # ruff
 /.ruff_cache
 
+# MyPy
+.mypy_cache
+
 # IDEs
 /.vscode
 

CONTRIBUTING.md

@@ -42,12 +42,13 @@ pixi run -e py38 test-py38
 
 ## Code quality
 
-Pixi Kernel uses Ruff to ensure a minimum standard of code quality. The code quality commands are
-encapsulated with Pixi:
+Pixi Kernel uses Ruff and MyPy to ensure a minimum standard of code quality. The code quality
+commands are encapsulated with Pixi:
 
 ```
 pixi run format
 pixi run lint
+pixi run type-check
 ```
 
 ## Making a release
@@ -76,7 +77,9 @@ Follow the steps below to add support for a new kernel:
 1. In a fresh Pixi environment install your kernel with `pixi install <kernel>`.
 2. Copy the new folders created at `.pixi/envs/default/share/jupyter/kernels/` to the `kernels`
    folder and commit the changes.
-3. Update the display name, metadata and command arguments in the kernel spec file `kernel.json`.
+3. Update the display name and command arguments in the kernel spec file `kernel.json`. The command
+   arguments should start with `["python", "-m", "pixi_kernel", <package_name>,
+<kernel_display_name>]` and all absolute paths should be removed.
 4. Update the Kernel Support table in the README.
 5. Add integration tests for the new kernel in the `tests/integration` folder and commit the
    changes.

kernels/pixi-kernel-bash/kernel.json

@@ -1,8 +1,10 @@
 {
   "argv": [
-    "pixi",
-    "run",
-    "--manifest-path={manifest-path}",
+    "python",
+    "-m",
+    "pixi_kernel",
+    "bash_kernel",
+    "Pixi - Bash",
     "python",
     "-m",
     "bash_kernel",
@@ -11,14 +13,5 @@
   ],
   "display_name": "Pixi - Bash",
   "env": { "PS1": "$" },
-  "language": "bash",
-  "metadata": {
-    "pixi-kernel": {
-      "package-name": "bash_kernel"
-    },
-    "kernel_provisioner": {
-      "provisioner_name": "pixi-provisioner",
-      "config": {}
-    }
-  }
+  "language": "bash"
 }

kernels/pixi-kernel-ir/kernel.json

@@ -1,8 +1,10 @@
 {
   "argv": [
-    "pixi",
-    "run",
-    "--manifest-path={manifest-path}",
+    "python",
+    "-m",
+    "pixi_kernel",
+    "r-irkernel",
+    "Pixi - R",
     "R",
     "--slave",
     "-e",
@@ -11,19 +13,5 @@
     "{connection_file}"
   ],
   "display_name": "Pixi - R",
-  "language": "R",
-  "env": {
-    "R_LIBS": "{manifest-path-parent}/.pixi/envs/default/lib/R/library",
-    "R_LIBS_SITE": "{manifest-path-parent}/.pixi/envs/default/lib/R/library",
-    "R_LIBS_USER": "{manifest-path-parent}/.pixi/envs/default/lib/R/library"
-  },
-  "metadata": {
-    "pixi-kernel": {
-      "package-name": "r-irkernel"
-    },
-    "kernel_provisioner": {
-      "provisioner_name": "pixi-provisioner",
-      "config": {}
-    }
-  }
+  "language": "R"
 }

kernels/pixi-kernel-python3/kernel.json

@@ -1,8 +1,10 @@
 {
   "argv": [
-    "pixi",
-    "run",
-    "--manifest-path={manifest-path}",
+    "python",
+    "-m",
+    "pixi_kernel",
+    "ipykernel",
+    "Pixi - Python 3 (ipykernel)",
     "python",
     "-m",
     "ipykernel_launcher",
@@ -12,13 +14,6 @@
   "display_name": "Pixi - Python 3 (ipykernel)",
   "language": "python",
   "metadata": {
-    "debugger": true,
-    "pixi-kernel": {
-      "package-name": "ipykernel"
-    },
-    "kernel_provisioner": {
-      "provisioner_name": "pixi-provisioner",
-      "config": {}
-    }
+    "debugger": true
   }
 }

kernels/pixi-kernel-xcpp11/kernel.json

@@ -1,22 +1,15 @@
 {
-  "display_name": "Pixi - C++11",
   "argv": [
-    "pixi",
-    "run",
-    "--manifest-path={manifest-path}",
+    "python",
+    "-m",
+    "pixi_kernel",
+    "xeus-cling",
+    "Pixi - C++11",
     "xcpp",
     "-f",
     "{connection_file}",
     "-std=c++11"
   ],
-  "language": "C++11",
-  "metadata": {
-    "pixi-kernel": {
-      "package-name": "xeus-cling"
-    },
-    "kernel_provisioner": {
-      "provisioner_name": "pixi-provisioner",
-      "config": {}
-    }
-  }
+  "display_name": "Pixi - C++11",
+  "language": "C++11"
 }

kernels/pixi-kernel-xcpp14/kernel.json

@@ -1,22 +1,15 @@
 {
-  "display_name": "Pixi - C++14",
   "argv": [
-    "pixi",
-    "run",
-    "--manifest-path={manifest-path}",
+    "python",
+    "-m",
+    "pixi_kernel",
+    "xeus-cling",
+    "Pixi - C++14",
     "xcpp",
     "-f",
     "{connection_file}",
     "-std=c++14"
   ],
-  "language": "C++14",
-  "metadata": {
-    "pixi-kernel": {
-      "package-name": "xeus-cling"
-    },
-    "kernel_provisioner": {
-      "provisioner_name": "pixi-provisioner",
-      "config": {}
-    }
-  }
+  "display_name": "Pixi - C++14",
+  "language": "C++14"
 }

kernels/pixi-kernel-xcpp17/kernel.json

@@ -1,22 +1,15 @@
 {
-  "display_name": "Pixi - C++17",
   "argv": [
-    "pixi",
-    "run",
-    "--manifest-path={manifest-path}",
+    "python",
+    "-m",
+    "pixi_kernel",
+    "xeus-cling",
+    "Pixi - C++17",
     "xcpp",
     "-f",
     "{connection_file}",
     "-std=c++17"
   ],
-  "language": "C++17",
-  "metadata": {
-    "pixi-kernel": {
-      "package-name": "xeus-cling"
-    },
-    "kernel_provisioner": {
-      "provisioner_name": "pixi-provisioner",
-      "config": {}
-    }
-  }
+  "display_name": "Pixi - C++17",
+  "language": "C++17"
 }