fix: build frontend and copilot on installation from source code (fork, git, local folder)

.github/actions/uv-python-install/action.yaml

@@ -32,6 +32,6 @@ runs:
       with:
         python-version: ${{ inputs.python-version }}
     - name: Install Python dependencies
-      run: uv sync ${{ inputs.extra-dependencies }}
+      run: uv sync --no-install-project --no-editable ${{ inputs.extra-dependencies }}
       shell: bash
       working-directory: ${{ inputs.working-directory }}

.github/workflows/lint-backend.yaml

@@ -28,5 +28,5 @@ jobs:
           changed-files: "true"
           args: "format --check"
       - name: Run Mypy
-        run: uv run mypy chainlit/
+        run: uv run --no-project mypy chainlit/
         working-directory: ${{ env.BACKEND_DIR }}

.github/workflows/publish.yaml

@@ -54,15 +54,11 @@ jobs:
         with:
           working-directory: ${{ env.BACKEND_DIR }}
 
-      - name: Build frontend and prepare assets
-        run: uv run python build.py
-        working-directory: ${{ env.BACKEND_DIR }}
-
       - name: Build Python distribution
         run: uv build
         working-directory: ${{ env.BACKEND_DIR }}
 
-      - name: List wheel contents
+      - name: Check frontend and copilot folder included
         run: |
           pip install wheel
           python -m wheel unpack dist/chainlit-*.whl -d unpacked

.github/workflows/pytest.yaml

@@ -26,5 +26,5 @@ jobs:
         run: pnpm run buildUi
         timeout-minutes: 5
       - name: Run Pytest
-        run: uv run pytest --cov=chainlit/
+        run: uv run --no-project pytest --cov=chainlit/
         working-directory: ${{ env.BACKEND_DIR }}

CONTRIBUTING.md

@@ -79,14 +79,6 @@ cd backend
 uv sync --extra tests --extra mypy --extra dev --extra custom-data
 ```
 
-### Build Frontend
-
-The following will build the frontend distributions locally. From the root of the repo:
-
-```sh
-pnpm run buildUi
-```
-
 ## Start the Chainlit server from source
 
 Start by running `backend/hello.py` as an example.

backend/build.py

@@ -1,19 +1,20 @@
 """Build script gets called on uv/pip build."""
 
-import os
 import pathlib
 import shutil
 import subprocess
 import sys
 
+from hatchling.builders.hooks.plugin.interface import BuildHookInterface
+
 
 class BuildError(Exception):
     """Custom exception for build failures"""
 
     pass
 
 
-def run_subprocess(cmd: list[str], cwd: os.PathLike) -> None:
+def run_subprocess(cmd: list[str], cwd: pathlib.Path) -> None:
     """
     Run a subprocess, allowing natural signal propagation.
 
@@ -26,19 +27,21 @@ def run_subprocess(cmd: list[str], cwd: os.PathLike) -> None:
     subprocess.run(cmd, cwd=cwd, check=True)
 
 
-def pnpm_install(project_root, pnpm_path):
+def pnpm_install(project_root: pathlib.Path, pnpm_path: str):
     run_subprocess([pnpm_path, "install", "--frozen-lockfile"], project_root)
 
 
-def pnpm_buildui(project_root, pnpm_path):
+def pnpm_buildui(project_root: pathlib.Path, pnpm_path: str):
     run_subprocess([pnpm_path, "buildUi"], project_root)
 
 
-def copy_directory(src, dst, description):
+def copy_directory(src: pathlib.Path, dst: pathlib.Path, description: str):
     """Copy directory with proper error handling"""
-    print(f"Copying {src} to {dst}")
+    print(f"Copying {description} from {src} to {dst}")
     try:
-        dst.mkdir(parents=True, exist_ok=True)
+        if dst.exists():
+            shutil.rmtree(dst)
+        dst.mkdir(parents=True)
         shutil.copytree(src, dst, dirs_exist_ok=True)
     except KeyboardInterrupt:
         print("\nInterrupt received during copy operation...")
@@ -50,14 +53,14 @@ def copy_directory(src, dst, description):
         raise BuildError(f"Failed to copy {src} to {dst}: {e!s}")
 
 
-def copy_frontend(project_root):
+def copy_frontend(project_root: pathlib.Path):
     """Copy the frontend dist directory to the backend for inclusion in the package."""
     backend_frontend_dir = project_root / "backend" / "chainlit" / "frontend" / "dist"
     frontend_dist = project_root / "frontend" / "dist"
     copy_directory(frontend_dist, backend_frontend_dir, "frontend assets")
 
 
-def copy_copilot(project_root):
+def copy_copilot(project_root: pathlib.Path):
     """Copy the copilot dist directory to the backend for inclusion in the package."""
     backend_copilot_dir = project_root / "backend" / "chainlit" / "copilot" / "dist"
     copilot_dist = project_root / "libs" / "copilot" / "dist"
@@ -70,14 +73,18 @@ def build():
     print(
         "\n-- Building frontend, this might take a while!\n\n"
         "   If you don't need to build the frontend and just want dependencies installed, use:\n"
-        "   `uv sync --no-build`\n"
+        "   `uv sync --no-install-project --no-editable`\n"
     )
 
     try:
         # Find directory containing this file
         backend_dir = pathlib.Path(__file__).resolve().parent
         project_root = backend_dir.parent
 
+        # Dirty hack to distinguish between building wheel from sdist and from source code
+        if not (project_root / "package.json").exists():
+            return
+
         pnpm = shutil.which("pnpm")
         if not pnpm:
             raise BuildError("pnpm not found!")
@@ -98,5 +105,6 @@ def build():
         sys.exit(1)
 
 
-if __name__ == "__main__":
-    build()
+class CustomBuildHook(BuildHookInterface):
+    def initialize(self, _, __):
+        build()

backend/pyproject.toml

@@ -116,17 +116,20 @@ exclude = [
   "chainlit/copilot/**/**/"
 ]
 
-[tool.hatch.build.targets.wheel]
-packages = ["chainlit"]
+[tool.hatch.build.hooks.custom]
+path = "build.py"
+
+[tool.hatch.build.targets.sdist]
 artifacts = [
-  "chainlit/frontend/dist/**/*",
-  "chainlit/copilot/dist/**/*"
+    "chainlit/frontend/dist/**/*",
+    "chainlit/copilot/dist/**/*"
 ]
 
-[tool.hatch.build.targets.sdist]
+[tool.hatch.build.targets.wheel]
+packages = ["chainlit"]
 artifacts = [
-  "chainlit/frontend/dist/**/*",
-  "chainlit/copilot/dist/**/*"
+    "chainlit/frontend/dist/**/*",
+    "chainlit/copilot/dist/**/*"
 ]
 
 [tool.hatch.version]