cli pyproject updating (langchain-ai#12945)

`langchain app add` and `langchain app remove` will now keep the
dependencies list updated.

---------

Co-authored-by: Nuno Campos <nuno@boringbits.io>

Author: Erick Friis

libs/cli/langchain_cli/dev_scripts.py

@@ -6,9 +6,8 @@
 
 from fastapi import FastAPI
 from langserve import add_routes
-from langserve.packages import get_langserve_export
 
-from langchain_cli.utils.packages import get_package_root
+from langchain_cli.utils.packages import get_langserve_export, get_package_root
 
 
 def create_demo_server(

libs/cli/langchain_cli/namespaces/app.py

@@ -9,7 +9,6 @@
 from typing import Dict, List, Optional, Tuple
 
 import typer
-from langserve.packages import get_langserve_export
 from typing_extensions import Annotated
 
 from langchain_cli.utils.events import create_events
@@ -19,7 +18,15 @@
     parse_dependencies,
     update_repo,
 )
-from langchain_cli.utils.packages import get_package_root
+from langchain_cli.utils.packages import (
+    LangServeExport,
+    get_langserve_export,
+    get_package_root,
+)
+from langchain_cli.utils.pyproject import (
+    add_dependencies_to_pyproject_toml,
+    remove_dependencies_from_pyproject_toml,
+)
 
 REPO_DIR = Path(typer.get_app_dir("langchain")) / "git_repos"
 
@@ -98,7 +105,8 @@ def add(
         grouped[key_tup] = lst
 
     installed_destination_paths: List[Path] = []
-    installed_exports: List[Dict] = []
+    installed_destination_names: List[str] = []
+    installed_exports: List[LangServeExport] = []
 
     for (git, ref), group_deps in grouped.items():
         if len(group_deps) == 1:
@@ -131,23 +139,38 @@ def add(
             copy_repo(source_path, destination_path)
             typer.echo(f" - Downloaded {dep['subdirectory']} to {inner_api_path}")
             installed_destination_paths.append(destination_path)
+            installed_destination_names.append(inner_api_path)
             installed_exports.append(langserve_export)
 
     if len(installed_destination_paths) == 0:
         typer.echo("No packages installed. Exiting.")
         return
 
-    cwd = Path.cwd()
-    installed_desination_strs = [
-        str(p.relative_to(cwd)) for p in installed_destination_paths
-    ]
-    cmd = ["pip", "install", "-e"] + installed_desination_strs
-    cmd_str = " \\\n  ".join(installed_desination_strs)
-    install_str = f"To install:\n\npip install -e \\\n  {cmd_str}"
-    typer.echo(install_str)
-
-    if typer.confirm("Run it?"):
-        subprocess.run(cmd, cwd=cwd)
+    try:
+        add_dependencies_to_pyproject_toml(
+            project_root / "pyproject.toml",
+            zip(installed_destination_names, installed_destination_paths),
+        )
+    except Exception:
+        # Can fail if user modified/removed pyproject.toml
+        typer.echo("Failed to add dependencies to pyproject.toml, continuing...")
+
+    try:
+        cwd = Path.cwd()
+        installed_destination_strs = [
+            str(p.relative_to(cwd)) for p in installed_destination_paths
+        ]
+    except ValueError:
+        # Can fail if the cwd is not a parent of the package
+        typer.echo("Failed to print install command, continuing...")
+    else:
+        cmd = ["pip", "install", "-e"] + installed_destination_strs
+        cmd_str = " \\\n  ".join(installed_destination_strs)
+        install_str = f"To install:\n\npip install -e \\\n  {cmd_str}"
+        typer.echo(install_str)
+
+        if typer.confirm("Run it?"):
+            subprocess.run(cmd, cwd=cwd)
 
     if typer.confirm("\nGenerate route code for these packages?", default=True):
         chain_names = []
@@ -187,20 +210,43 @@ def add(
 @app_cli.command()
 def remove(
     api_paths: Annotated[List[str], typer.Argument(help="The API paths to remove")],
+    *,
+    project_dir: Annotated[
+        Optional[Path], typer.Option(help="The project directory")
+    ] = None,
 ):
     """
     Removes the specified package from the current LangServe app.
     """
+
+    project_root = get_package_root(project_dir)
+
+    project_pyproject = project_root / "pyproject.toml"
+
+    package_root = project_root / "packages"
+
+    remove_deps: List[str] = []
+
     for api_path in api_paths:
-        package_dir = Path.cwd() / "packages" / api_path
+        package_dir = package_root / api_path
         if not package_dir.exists():
-            typer.echo(f"Endpoint {api_path} does not exist. Skipping...")
+            typer.echo(f"Package {api_path} does not exist. Skipping...")
             continue
-        pyproject = package_dir / "pyproject.toml"
-        langserve_export = get_langserve_export(pyproject)
-        typer.echo(f"Removing {langserve_export['package_name']}...")
-
-        shutil.rmtree(package_dir)
+        try:
+            pyproject = package_dir / "pyproject.toml"
+            langserve_export = get_langserve_export(pyproject)
+            typer.echo(f"Removing {langserve_export['package_name']}...")
+
+            shutil.rmtree(package_dir)
+            remove_deps.append(api_path)
+        except Exception:
+            pass
+
+    try:
+        remove_dependencies_from_pyproject_toml(project_pyproject, remove_deps)
+    except Exception:
+        # Can fail if user modified/removed pyproject.toml
+        typer.echo("Failed to remove dependencies from pyproject.toml.")
 
 
 @app_cli.command()

libs/cli/langchain_cli/namespaces/template.py

@@ -9,10 +9,9 @@
 from typing import Optional
 
 import typer
-from langserve.packages import get_langserve_export
 from typing_extensions import Annotated
 
-from langchain_cli.utils.packages import get_package_root
+from langchain_cli.utils.packages import get_langserve_export, get_package_root
 
 package_cli = typer.Typer(no_args_is_help=True, add_completion=False)
 

libs/cli/langchain_cli/project_template/pyproject.toml

@@ -1,22 +1,18 @@
 [tool.poetry]
-name = "langservehub-template"
+name = "__app_name__"
 version = "0.1.0"
 description = ""
 authors = ["Your Name <you@example.com>"]
 readme = "README.md"
 
 [tool.poetry.dependencies]
 python = "^3.11"
-sse-starlette = "^1.6.5"
-tomli-w = "^1.0.0"
 uvicorn = "^0.23.2"
-fastapi = "^0.103.2"
-langserve = ">=0.0.16"
+langserve = {extras = ["server"], version = ">=0.0.22"}
 
-[tool.poetry.group.dev.dependencies]
-uvicorn = "^0.23.2"
-pygithub = "^2.1.1"
 
+[tool.poetry.group.dev.dependencies]
+langchain-cli = ">=0.0.15"
 
 [build-system]
 requires = ["poetry-core"]

libs/cli/langchain_cli/utils/packages.py

@@ -1,5 +1,7 @@
 from pathlib import Path
-from typing import Optional, Set
+from typing import Any, Dict, Optional, Set, TypedDict
+
+from tomlkit import load
 
 
 def get_package_root(cwd: Optional[Path] = None) -> Path:
@@ -14,3 +16,30 @@ def get_package_root(cwd: Optional[Path] = None) -> Path:
             return package_root
         package_root = package_root.parent
     raise FileNotFoundError("No pyproject.toml found")
+
+
+class LangServeExport(TypedDict):
+    """
+    Fields from pyproject.toml that are relevant to LangServe
+
+    Attributes:
+        module: The module to import from, tool.langserve.export_module
+        attr: The attribute to import from the module, tool.langserve.export_attr
+        package_name: The name of the package, tool.poetry.name
+    """
+
+    module: str
+    attr: str
+    package_name: str
+
+
+def get_langserve_export(filepath: Path) -> LangServeExport:
+    with open(filepath) as f:
+        data: Dict[str, Any] = load(f)
+    try:
+        module = data["tool"]["langserve"]["export_module"]
+        attr = data["tool"]["langserve"]["export_attr"]
+        package_name = data["tool"]["poetry"]["name"]
+    except KeyError as e:
+        raise KeyError("Invalid LangServe PyProject.toml") from e
+    return LangServeExport(module=module, attr=attr, package_name=package_name)

libs/cli/langchain_cli/utils/pyproject.py

@@ -0,0 +1,45 @@
+from pathlib import Path
+from typing import Any, Dict, Iterable
+
+from tomlkit import dump, inline_table, load
+from tomlkit.items import InlineTable
+
+
+def _get_dep_inline_table(path: Path) -> InlineTable:
+    dep = inline_table()
+    dep.update({"path": str(path), "develop": True})
+    return dep
+
+
+def add_dependencies_to_pyproject_toml(
+    pyproject_toml: Path, local_editable_dependencies: Iterable[tuple[str, Path]]
+) -> None:
+    """Add dependencies to pyproject.toml."""
+    with open(pyproject_toml, encoding="utf-8") as f:
+        # tomlkit types aren't amazing - treat as Dict instead
+        pyproject: Dict[str, Any] = load(f)
+        pyproject["tool"]["poetry"]["dependencies"].update(
+            {
+                name: _get_dep_inline_table(loc.relative_to(pyproject_toml.parent))
+                for name, loc in local_editable_dependencies
+            }
+        )
+    with open(pyproject_toml, "w", encoding="utf-8") as f:
+        dump(pyproject, f)
+
+
+def remove_dependencies_from_pyproject_toml(
+    pyproject_toml: Path, local_editable_dependencies: Iterable[str]
+) -> None:
+    """Remove dependencies from pyproject.toml."""
+    with open(pyproject_toml, encoding="utf-8") as f:
+        pyproject: Dict[str, Any] = load(f)
+        # tomlkit types aren't amazing - treat as Dict instead
+        dependencies = pyproject["tool"]["poetry"]["dependencies"]
+        for name in local_editable_dependencies:
+            try:
+                del dependencies[name]
+            except KeyError:
+                pass
+    with open(pyproject_toml, "w", encoding="utf-8") as f:
+        dump(pyproject, f)