feat(dsl): chainable .setup() on all toolchains (Python + TypeScript)

crates/hm-dsl-engine/harmont-py/harmont/_cmake.py

@@ -23,9 +23,9 @@
 
 import re
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Any, overload
+from typing import TYPE_CHECKING, Any, Self, overload
 
-from ._toolchain import make_install_chain
+from ._toolchain import advance_install, make_install_chain
 from .cache import CacheForever, CacheOnChange
 
 if TYPE_CHECKING:
@@ -232,6 +232,28 @@ class CMakeToolchain:
     ccache: bool
     generator: str
 
+    def setup(
+        self,
+        cmd: str,
+        *,
+        cwd: str | None = None,
+        label: str | None = None,
+        cache: CachePolicy | None = None,
+        env: dict[str, str] | None = None,
+    ) -> Self:
+        """Append a post-install command and return an advanced toolchain; chainable.
+
+        Use for prep steps the toolchain's actions must depend on but that the SDK
+        does not model natively — code generation, fixtures, extra tooling. Every
+        ``CMakeProject`` spawned from the returned toolchain forks from this step,
+        so prep runs before the configure+build.
+
+        Examples:
+            >>> import harmont as hm
+            >>> tc = hm.cmake().setup("./scripts/gen-headers.sh")
+        """
+        return advance_install(self, cmd, cwd=cwd, label=label, cache=cache, env=env)
+
     def project(
         self,
         *,

crates/hm-dsl-engine/harmont-py/harmont/_elixir.py

@@ -11,10 +11,10 @@
 import re
 from dataclasses import dataclass
 from dataclasses import field as dataclass_field
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Self
 
-from ._toolchain import make_install_chain
-from .cache import CacheForever, CacheOnChange
+from ._toolchain import advance_install, make_install_chain
+from .cache import CacheForever, CacheOnChange, CachePolicy
 
 if TYPE_CHECKING:
     from ._step import Step
@@ -73,6 +73,29 @@ class ElixirProject:
     installed: Step
     _plt_step: Step | None = dataclass_field(default=None, init=False, repr=False)
 
+    def setup(
+        self,
+        cmd: str,
+        *,
+        cwd: str | None = None,
+        label: str | None = None,
+        cache: CachePolicy | None = None,
+        env: dict[str, str] | None = None,
+    ) -> Self:
+        """Append a post-install command and return an advanced project; chainable.
+
+        Use for prep steps the toolchain's actions must depend on but that the SDK
+        does not model natively — code generation, fixtures, extra tooling. The
+        returned object's action methods (``compile``/``test``/…) fork from this
+        step, so they all see its results.
+
+        Examples:
+            >>> import harmont as hm
+            >>> proj = hm.elixir(path="elixir").setup("mix proto.gen")
+            >>> hm.pipeline([proj.compile(), proj.test()])
+        """
+        return advance_install(self, cmd, cwd=cwd, label=label, cache=cache, env=env)
+
     def _emit(self, cmd: str, default_label: str, **kw: Any) -> Step:
         if kw.get("label") is None:
             kw["label"] = default_label

crates/hm-dsl-engine/harmont-py/harmont/_go.py

@@ -9,13 +9,14 @@
 
 import re
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Self
 
-from ._toolchain import make_install_chain
+from ._toolchain import advance_install, make_install_chain
 from .cache import CacheForever
 
 if TYPE_CHECKING:
     from ._step import Step
+    from .cache import CachePolicy
 
 APT_PACKAGES = ("curl", "ca-certificates", "git")
 
@@ -46,6 +47,27 @@ class GoToolchain:
     path: str
     installed: Step
 
+    def setup(
+        self,
+        cmd: str,
+        *,
+        cwd: str | None = None,
+        label: str | None = None,
+        cache: CachePolicy | None = None,
+        env: dict[str, str] | None = None,
+    ) -> Self:
+        """Append a post-install command and return an advanced toolchain; chainable.
+
+        Use for prep steps the toolchain's actions must depend on but that the SDK
+        does not model natively — code generation, fixtures, extra tooling. The
+        returned object's action methods fork from this step.
+
+        Examples:
+            >>> import harmont as hm
+            >>> tc = hm.go(path=".").setup("go generate ./...")
+        """
+        return advance_install(self, cmd, cwd=cwd, label=label, cache=cache, env=env)
+
     def _emit(self, cmd: str, default_label: str, **kw: Any) -> Step:
         if kw.get("label") is None:
             kw["label"] = default_label

crates/hm-dsl-engine/harmont-py/harmont/_js.py

@@ -21,10 +21,11 @@
 
 import re
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Any, Literal
+from typing import TYPE_CHECKING, Any, Literal, Self
 
 from ._detect import detect
 from ._toolchain import (
+    advance_install,
     bun_install_cmd,
     deno_install_cmd,
     make_install_chain,
@@ -34,6 +35,7 @@
 
 if TYPE_CHECKING:
     from ._step import Step
+    from .cache import CachePolicy
 
 Runtime = Literal["node", "bun", "deno"]
 PackageManager = Literal["npm", "pnpm", "yarn-classic", "yarn-berry", "bun", "deno"]
@@ -124,6 +126,27 @@ class JsProject:
     run_prefix: str
     tag: str
 
+    def setup(
+        self,
+        cmd: str,
+        *,
+        cwd: str | None = None,
+        label: str | None = None,
+        cache: CachePolicy | None = None,
+        env: dict[str, str] | None = None,
+    ) -> Self:
+        """Append a post-install command and return an advanced project; chainable.
+
+        Use for prep steps the toolchain's actions must depend on but that the SDK
+        does not model natively — code generation, fixtures, extra tooling. The
+        returned object's action methods fork from this step.
+
+        Examples:
+            >>> import harmont as hm
+            >>> proj = hm.js.project(path=".").setup("npm run codegen")
+        """
+        return advance_install(self, cmd, cwd=cwd, label=label, cache=cache, env=env)
+
     def install(self) -> Step:
         """Return the dependency-install step (the unambiguous default leaf)."""
         return self.installed

crates/hm-dsl-engine/harmont-py/harmont/_python.py

@@ -17,13 +17,14 @@
 
 import re
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Self
 
-from ._toolchain import make_install_chain
+from ._toolchain import advance_install, make_install_chain
 from .cache import CacheForever, CacheOnChange
 
 if TYPE_CHECKING:
     from ._step import Step
+    from .cache import CachePolicy
 
 APT_PACKAGES = ("curl", "ca-certificates", "python3", "python3-venv")
 
@@ -60,6 +61,27 @@ class PythonToolchain:
     path: str
     installed: Step  # uv-sync Step
 
+    def setup(
+        self,
+        cmd: str,
+        *,
+        cwd: str | None = None,
+        label: str | None = None,
+        cache: CachePolicy | None = None,
+        env: dict[str, str] | None = None,
+    ) -> Self:
+        """Append a post-install command and return an advanced toolchain; chainable.
+
+        Use for prep steps the toolchain's actions must depend on but that the SDK
+        does not model natively — code generation, fixtures, extra tooling. The
+        returned object's action methods fork from this step.
+
+        Examples:
+            >>> import harmont as hm
+            >>> tc = hm.python(path=".").setup("uv run python scripts/codegen.py")
+        """
+        return advance_install(self, cmd, cwd=cwd, label=label, cache=cache, env=env)
+
     def _emit(self, cmd: str, default_label: str, **kw: Any) -> Step:
         if kw.get("label") is None:
             kw["label"] = default_label

crates/hm-dsl-engine/harmont-py/harmont/_rust.py

@@ -11,10 +11,10 @@
 import re
 import shlex
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Self
 
 from ._cargo import CargoOpts, cargo_flags
-from ._toolchain import make_install_chain
+from ._toolchain import advance_install, make_install_chain
 from .cache import CacheForever, CacheOnChange
 
 if TYPE_CHECKING:
@@ -151,6 +151,28 @@ class RustToolchain:
     path: str
     installed: Step
 
+    def setup(
+        self,
+        cmd: str,
+        *,
+        cwd: str | None = None,
+        label: str | None = None,
+        cache: CachePolicy | None = None,
+        env: dict[str, str] | None = None,
+    ) -> Self:
+        """Append a post-install command and return an advanced toolchain; chainable.
+
+        Use for prep steps the toolchain's actions must depend on but that the SDK
+        does not model natively — code generation, fixtures, extra tooling. The
+        returned object's action methods (and projects spawned from it) fork from
+        this step, so prep runs before the cargo warmup precompile.
+
+        Examples:
+            >>> import harmont as hm
+            >>> tc = hm.rust.toolchain().setup("cargo install sqlx-cli")
+        """
+        return advance_install(self, cmd, cwd=cwd, label=label, cache=cache, env=env)
+
     def _wrap(self, cargo: str) -> str:
         return f". $HOME/.cargo/env && cd {self.path} && {cargo}"
 

crates/hm-dsl-engine/harmont-py/harmont/_toolchain.py

@@ -13,8 +13,9 @@
 
 from __future__ import annotations
 
+import dataclasses
 from datetime import timedelta
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Protocol, TypeVar
 
 from ._step import scratch
 from .cache import CacheTTL
@@ -27,6 +28,38 @@
 APT_TTL = timedelta(days=1)
 
 
+class _HasInstalled(Protocol):
+    # Read-only member (property form) so frozen-dataclass toolchains, whose
+    # `installed` field is read-only, satisfy the protocol. A bare
+    # `installed: Step` annotation declares a *writable* member, which frozen
+    # instances do not match.
+    @property
+    def installed(self) -> Step: ...
+
+
+_ProjectT = TypeVar("_ProjectT", bound="_HasInstalled")
+
+
+def advance_install(
+    project: _ProjectT,
+    cmd: str,
+    *,
+    cwd: str | None = None,
+    label: str | None = None,
+    cache: CachePolicy | None = None,
+    env: dict[str, str] | None = None,
+) -> _ProjectT:
+    """Return a copy of a toolchain object with one command appended to its
+    install chain. Every action method emitted from the returned object forks
+    from the new step. Shared implementation behind each toolchain's ``setup()``.
+    """
+    new_installed = project.installed.sh(cmd, cwd=cwd, label=label, cache=cache, env=env)
+    # All callers are frozen dataclasses carrying an `installed: Step` field, but
+    # the Protocol bound cannot express "is a dataclass", so the replace below
+    # cannot satisfy its DataclassInstance upper bound — hence the narrow ignore.
+    return dataclasses.replace(project, installed=new_installed)  # ty: ignore[invalid-argument-type]
+
+
 def apt_install_cmd(packages: tuple[str, ...]) -> str:
     """Single shell string: ``apt-get update && apt-get install -y <pkgs>``."""
     pkgs = " ".join(packages)

crates/hm-dsl-engine/harmont-py/harmont/_zig.py

@@ -19,13 +19,14 @@
 
 import re
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, Any, overload
+from typing import TYPE_CHECKING, Any, Self, overload
 
-from ._toolchain import make_install_chain
+from ._toolchain import advance_install, make_install_chain
 from .cache import CacheForever
 
 if TYPE_CHECKING:
     from ._step import Step
+    from .cache import CachePolicy
 
 APT_PACKAGES = ("curl", "ca-certificates", "xz-utils")
 
@@ -66,6 +67,27 @@ class ZigProject:
     path: str
     installed: Step
 
+    def setup(
+        self,
+        cmd: str,
+        *,
+        cwd: str | None = None,
+        label: str | None = None,
+        cache: CachePolicy | None = None,
+        env: dict[str, str] | None = None,
+    ) -> Self:
+        """Append a post-install command and return an advanced project; chainable.
+
+        Use for prep steps the toolchain's actions must depend on but that the SDK
+        does not model natively — code generation, fixtures, extra tooling. The
+        returned object's action methods fork from this step.
+
+        Examples:
+            >>> import harmont as hm
+            >>> proj = hm.zig(path=".").setup("zig build gen")
+        """
+        return advance_install(self, cmd, cwd=cwd, label=label, cache=cache, env=env)
+
     def _emit(self, cmd: str, default_label: str, **kw: Any) -> Step:
         if kw.get("label") is None:
             kw["label"] = default_label
@@ -106,6 +128,28 @@ class ZigToolchain:
     version: str
     installed: Step
 
+    def setup(
+        self,
+        cmd: str,
+        *,
+        cwd: str | None = None,
+        label: str | None = None,
+        cache: CachePolicy | None = None,
+        env: dict[str, str] | None = None,
+    ) -> Self:
+        """Append a post-install command and return an advanced toolchain; chainable.
+
+        Use for prep steps the toolchain's actions must depend on but that the SDK
+        does not model natively — code generation, fixtures, extra tooling. Every
+        ``ZigProject`` spawned from the returned toolchain forks from this step.
+
+        Examples:
+            >>> import harmont as hm
+            >>> tc = hm.zig().setup("zig build gen")
+            >>> hm.pipeline([tc.project("lib-a").test()])
+        """
+        return advance_install(self, cmd, cwd=cwd, label=label, cache=cache, env=env)
+
     def project(self, path: str = ".") -> ZigProject:
         """Create a ``ZigProject`` rooted at ``path`` from this toolchain.