thiagokokada · thiagokokada · Oct 25, 2023 · Oct 25, 2023 · Oct 25, 2023 · Oct 25, 2023
diff --git a/README.md b/README.md
@@ -95,7 +95,7 @@ There are also some other options, check them using `--help` flag on each
 program. Example for `nix-alien`:
 
 ```console
-usage: nix-alien [-h] [--version] [-l LIBRARY] [-p PACKAGE] [-r] [-d PATH] [-P] [-E] [-s] [-f] program ...
+usage: nix-alien [-h] [--version] [-l LIBRARY] [-p PACKAGE] [-c CANDIDATE] [-r] [-d PATH] [-P] [-E] [-s] [-f] program ...
 
 positional arguments:
   program               Program to run
@@ -108,6 +108,8 @@ options:
                         Additional library to search. May be passed multiple times
   -p PACKAGE, --additional-packages PACKAGE
                         Additional package to add. May be passed multiple times
+  -c CANDIDATE, --select-candidates CANDIDATE
+                        Library candidates that will be auto-selected if found. Useful for automation. May be passed multiple times
   -r, --recreate        Recreate 'default.nix' file if exists
   -d PATH, --destination PATH
                         Path where 'default.nix' file will be created
@@ -120,8 +122,8 @@ options:
 
 ### Usage without installing
 
-You can run the scripts from this repo directly without clonning or
-installing them, assuming you're using [a resonable up-to-date nix and enabled
+You can run the scripts from this repo directly without clonning or installing
+them, assuming you're using [a resonable up-to-date nix and enabled
 experimental Flakes support](https://nixos.wiki/wiki/Flakes#Enable_flakes).
 
 ```console

diff --git a/flake.lock b/flake.lock
diff --git a/flake.nix b/flake.nix
@@ -7,7 +7,7 @@
       flake = false;
     };
     flake-utils.url = "github:numtide/flake-utils";
-    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     nix-index-database.url = "github:Mic92/nix-index-database";
   };
 

diff --git a/nix_alien/_impl.py b/nix_alien/_impl.py
@@ -22,10 +22,11 @@ def create_template_drv(
     silent: bool = False,
     additional_libs: Iterable[str] = (),
     additional_packages: Iterable[str] = (),
+    select_candidates: Iterable[str] = (),
     _indent: int = 4,
 ) -> str:
     path = Path(program).expanduser()
-    packages = find_libs(path, silent, additional_libs)
+    packages = find_libs(path, silent, additional_libs, select_candidates)
 
     return read_template(template).safe_substitute(
         __name__=REMOVE_WHITESPACES.sub("_", path.name),
@@ -46,14 +47,20 @@ def create(
     silent: bool = False,
     additional_libs: Iterable[str] = (),
     additional_packages: Iterable[str] = (),
+    select_candidates: Iterable[str] = (),
 ) -> None:
     if recreate:
         destination.unlink(missing_ok=True)
 
     if not destination.exists():
         destination.parent.mkdir(parents=True, exist_ok=True)
         fhs_shell = create_template_drv(
-            template, program, silent, additional_libs, additional_packages
+            template,
+            program,
+            silent,
+            additional_libs,
+            additional_packages,
+            select_candidates,
         )
         with open(destination, "w", encoding="locale") as file:
             file.write(fhs_shell)
@@ -82,10 +89,11 @@ def create_template_drv_flake(
     silent: bool = False,
     additional_libs: Iterable[str] = (),
     additional_packages: Iterable[str] = (),
+    select_candidates: Iterable[str] = (),
     _indent: int = 12,
 ) -> str:
     path = Path(program).expanduser()
-    libs = find_libs(path, silent, additional_libs)
+    libs = find_libs(path, silent, additional_libs, select_candidates)
 
     return read_template(template).safe_substitute(
         __name__=path.name,
@@ -106,14 +114,20 @@ def create_flake(
     silent: bool = False,
     additional_libs: Iterable[str] = (),
     additional_packages: Iterable[str] = (),
+    select_candidates: Iterable[str] = (),
 ) -> None:
     if recreate:
         destination.unlink(missing_ok=True)
 
     if not destination.exists():
         destination.parent.mkdir(parents=True, exist_ok=True)
         fhs_shell = create_template_drv_flake(
-            template, program, silent, additional_libs, additional_packages
+            template,
+            program,
+            silent,
+            additional_libs,
+            additional_packages,
+            select_candidates,
         )
         with open(destination, "w", encoding="locale") as file:
             file.write(fhs_shell)
@@ -163,6 +177,20 @@ def main(
         action="append",
         default=[],
     )
+    parser.add_argument(
+        "-c",
+        "--select-candidates",
+        metavar="CANDIDATE",
+        help=" ".join(
+            [
+                "Library candidates that will be auto-selected if found.",
+                "Useful for automation.",
+                "May be passed multiple times",
+            ]
+        ),
+        action="append",
+        default=[],
+    )
     parser.add_argument(
         "-r",
         "--recreate",
@@ -231,6 +259,7 @@ def main(
             recreate=parsed_args.recreate,
             additional_libs=parsed_args.additional_libs,
             additional_packages=parsed_args.additional_packages,
+            select_candidates=parsed_args.select_candidates,
             silent=parsed_args.silent,
         )
     else:
@@ -241,5 +270,6 @@ def main(
             recreate=parsed_args.recreate,
             additional_libs=parsed_args.additional_libs,
             additional_packages=parsed_args.additional_packages,
+            select_candidates=parsed_args.select_candidates,
             silent=parsed_args.silent,
         )
diff --git a/nix_alien/fhs_env.py b/nix_alien/fhs_env.py
@@ -31,6 +31,7 @@ def create_fhs_env(
     silent: bool = False,
     additional_libs: Iterable[str] = (),
     additional_packages: Iterable[str] = (),
+    select_candidates: Iterable[str] = (),
 ) -> None:
     return _impl.create(
         template=TEMPLATE,
@@ -42,6 +43,7 @@ def create_fhs_env(
         silent=silent,
         additional_libs=additional_libs,
         additional_packages=additional_packages,
+        select_candidates=select_candidates,
     )
 
 
@@ -68,6 +70,7 @@ def create_fhs_env_flake(
     silent: bool = False,
     additional_libs: Iterable[str] = (),
     additional_packages: Iterable[str] = (),
+    select_candidates: Iterable[str] = (),
 ) -> None:
     return _impl.create_flake(
         template=FLAKE_TEMPLATE,
@@ -78,6 +81,7 @@ def create_fhs_env_flake(
         silent=silent,
         additional_libs=additional_libs,
         additional_packages=additional_packages,
+        select_candidates=select_candidates,
     )
 
 

diff --git a/nix_alien/libs.py b/nix_alien/libs.py
@@ -39,6 +39,7 @@ def find_libs(
     path: Union[Path, str],
     silent: bool = False,
     additional_libs: Iterable[str] = (),
+    select_candidates: Iterable[str] = (),
 ) -> dict[str, Optional[str]]:
     _print = get_print(silent)
     path = Path(path).expanduser()
@@ -55,25 +56,34 @@ def find_libs(
             continue
 
         candidates = find_lib_candidates(dep.soname)
+        selected_candidate = None
+
         if len(candidates) == 0:
             _print(f"No candidate found for '{dep.soname}'", file=sys.stderr)
-            selected_candidate = None
         elif len(candidates) == 1:
             selected_candidate = candidates[0]
         else:
-            intersection = set(resolved_deps.values()).intersection(candidates)
-            if intersection:
-                # Can be any candidate really, lets pick the first one
-                selected_candidate = intersection.pop()
-            else:
-                fzf_options = join(
-                    [
-                        "--cycle",
-                        "--prompt",
-                        f"Select candidate for '{dep.soname}'> ",
-                    ]
-                )
-                selected_candidate = fzf.prompt(candidates, fzf_options)[0]
+            # Prioritise user selected candidates
+            maybe_selected_candidates = (
+                c for c in select_candidates if c in candidates
+            )
+            selected_candidate = next(maybe_selected_candidates, None)
+
+            # Try to find an dependency that is already solved
+            if not selected_candidate:
+                intersection = (d for d in resolved_deps.values() if d in candidates)
+                selected_candidate = next(intersection, None)
+
+                # Show FZF to allow user to select the best dependency
+                if not selected_candidate:
+                    fzf_options = join(
+                        [
+                            "--cycle",
+                            "--prompt",
+                            f"Select candidate for '{dep.soname}'> ",
+                        ]
+                    )
+                    selected_candidate = fzf.prompt(candidates, fzf_options)[0]
 
         _print(
             f"Selected candidate for '{dep.soname}': {selected_candidate}",
@@ -105,6 +115,20 @@ def main(args=None):
         action="append",
         default=[],
     )
+    parser.add_argument(
+        "-c",
+        "--select-candidates",
+        metavar="CANDIDATE",
+        help=" ".join(
+            [
+                "Library candidates that will be auto-selected if found.",
+                "Useful for automation.",
+                "May be passed multiple times",
+            ]
+        ),
+        action="append",
+        default=[],
+    )
     parser.add_argument("-j", "--json", help="Output as json", action="store_true")
     parser.add_argument(
         "-s",
@@ -118,6 +142,7 @@ def main(args=None):
         parsed_args.program,
         silent=parsed_args.silent,
         additional_libs=parsed_args.additional_libs,
+        select_candidates=parsed_args.select_candidates,
     )
 
     if parsed_args.json:

diff --git a/nix_alien/nix_ld.py b/nix_alien/nix_ld.py
@@ -31,6 +31,7 @@ def create_nix_ld(
     silent: bool = False,
     additional_libs: Iterable[str] = (),
     additional_packages: Iterable[str] = (),
+    select_candidates: Iterable[str] = (),
 ) -> None:
     return _impl.create(
         template=TEMPLATE,
@@ -42,6 +43,7 @@ def create_nix_ld(
         silent=silent,
         additional_libs=additional_libs,
         additional_packages=additional_packages,
+        select_candidates=select_candidates,
     )
 
 
@@ -68,6 +70,7 @@ def create_nix_ld_flake(
     silent: bool = False,
     additional_libs: Iterable[str] = (),
     additional_packages: Iterable[str] = (),
+    select_candidates: Iterable[str] = (),
 ) -> None:
     return _impl.create_flake(
         template=FLAKE_TEMPLATE,
@@ -78,6 +81,7 @@ def create_nix_ld_flake(
         silent=silent,
         additional_libs=additional_libs,
         additional_packages=additional_packages,
+        select_candidates=select_candidates,
     )
 
 

diff --git a/tests/test_libs.py b/tests/test_libs.py
@@ -109,7 +109,9 @@ def test_find_libs_when_multiple_candidates_found(
         DependencyMock(soname="libbar.so", path="/lib/libbar.so", found=False),
         DependencyMock(soname="libbar.so", path="/lib/libbar.so", found=False),
     ]
-    mock_subprocess.run.return_value = CompletedProcessMock(stdout="foo.out\nbar.out")
+    mock_subprocess.run.return_value = CompletedProcessMock(
+        stdout="\n".join(["foo.out", "bar.out"])
+    )
     # On the second time, this will take the candidate from intersection
     mock_fzf.prompt.side_effect = [["foo.out"]]
     assert libs.find_libs("xyz", silent=True, additional_libs=["libquux.so"]) == {
@@ -122,6 +124,38 @@ def test_find_libs_when_multiple_candidates_found(
     assert err == ""
 
 
+@patch("nix_alien.libs.list_dependencies", autospec=True)
+@patch("nix_alien.libs.subprocess", autospec=True)
+def test_find_libs_when_select_candidates_is_used(
+    mock_subprocess,
+    mock_list_dependencies,
+    capsys,
+):
+    mock_list_dependencies.return_value = [
+        DependencyMock(soname="libfoo.so", path="/lib/libfoo.so", found=False),
+        DependencyMock(soname="libbar.so", path="/lib/libbar.so", found=False),
+        DependencyMock(soname="libquux.so", path="/lib/libbar.so", found=False),
+    ]
+    mock_subprocess.run.return_value = CompletedProcessMock(
+        stdout="\n".join(["foo.out", "bar.out"])
+    )
+    assert libs.find_libs("xyz", select_candidates=["foo.out"]) == {
+        "libfoo.so": "foo.out",
+        "libbar.so": "foo.out",
+        "libquux.so": "foo.out",
+    }
+
+    _, err = capsys.readouterr()
+    assert (
+        err
+        == """\
+[nix-alien] Selected candidate for 'libfoo.so': foo.out
+[nix-alien] Selected candidate for 'libbar.so': foo.out
+[nix-alien] Selected candidate for 'libquux.so': foo.out
+"""
+    )
+
+
 def test_get_unique_packages():
     assert libs.get_unique_packages({}) == []
 
@@ -170,8 +204,22 @@ def test_main_with_args(mock_subprocess, mock_list_dependencies, capsys):
         DependencyMock(soname="libfoo.so", path="/lib/libfoo.so", found=False),
         DependencyMock(soname="libbar.so", path="/lib/libbar.so", found=False),
     ]
-    mock_subprocess.run.return_value = CompletedProcessMock(stdout="foo.out")
-    libs.main(["xyz", "--json", "--silent", "-l", "libqux.so", "-l", "libquux.so"])
+    mock_subprocess.run.return_value = CompletedProcessMock(
+        stdout="\n".join(["foo.out", "bar.out"])
+    )
+    libs.main(
+        [
+            "xyz",
+            "--json",
+            "--silent",
+            "-l",
+            "libqux.so",
+            "-l",
+            "libquux.so",
+            "-c",
+            "foo.out",
+        ]
+    )
 
     out, err = capsys.readouterr()
     assert json.loads(out) == {