feat: Add support for legacy files

.github/workflows/release.yml

@@ -4,6 +4,7 @@ on:
   workflow_run:
     workflows: [Build]
     types: [completed]
+    branches: [main]
 
 concurrency:
   group: release

README.md

@@ -127,6 +127,14 @@ devShells.default = pkgs.mkShell {
 `packagesFromVersionsFile` is of the form `{ “<plugin-1>” = <package-1>;
 "<plugin-2>" = <package-2>; ... }`.
 
+## Version Files
+
+As of version `2.1.0`, asdf2nix now supports legacy version files in the same
+way that
+[asdf](https://asdf-vm.com/manage/configuration.html#legacy-version-file) does.
+Check the version files [test suite](tests/version_files_test.nix) for more
+information on how this feature works.
+
 ## Plugins
 
 In an asdf2nix context, a plugin’s primary goal is to determine whether a

flake.nix

@@ -7,7 +7,8 @@
     in
     {
       lib.packagesFromVersionsFile =
-        { versionsFile
+        { versionsFile ? null
+        , legacyVersionFiles ? { }
         , system ? builtins.currentSystem
         , plugins ? { }
         , skipMissingPlugins ? false
@@ -22,10 +23,46 @@
               in
               {
                 name = builtins.elemAt pluginAndVersion 0;
-                version = builtins.elemAt pluginAndVersion 1;
+                value = builtins.elemAt pluginAndVersion 1;
               });
-          filterPlugins = builtins.filter
-            ({ name, ... }:
+          toolVersions =
+            if versionsFile == null
+            then { }
+            else
+              builtins.listToAttrs
+                (parseVersions
+                  (removeComments
+                    (fileLines versionsFile)));
+          legacyVersions =
+            builtins.mapAttrs
+              (_: file: lib.fileContents file)
+              legacyVersionFiles;
+          versions =
+            lib.throwIf (versionsFile == null && legacyVersionFiles == { })
+              ''
+                No version files provided. Try with `versionsFile`:
+
+                ```
+                packagesFromVersionsFile {
+                  versionsFile = ./.tool-versions;
+                  ...
+                }
+                ```
+
+                Or `legacyVersionFiles`:
+
+                ```
+                packagesFromVersionsFile {
+                  legacyVersionFiles = {
+                    python = ./.python-version;
+                  };
+                  ...
+                }
+                ```
+              ''
+              toolVersions // legacyVersions;
+          filterPlugins = lib.filterAttrs
+            (name: _:
               let
                 hasPlugin = builtins.hasAttr name plugins;
               in
@@ -56,8 +93,8 @@
                 lib.warnIf
                 (!hasPlugin) "Skipping \"${name}\" plugin"
                 hasPlugin);
-          findPackages = builtins.map
-            ({ name, version }:
+          findPackages = builtins.mapAttrs
+            (name: version:
               let
                 plugin = plugins.${name};
               in
@@ -70,18 +107,13 @@
                   > nix flake lock --update-input <asdf2nix-${name}>
                   ```
                 ''
+                plugin.packageFromVersion
                 {
-                  inherit name;
-                  value = plugin.packageFromVersion { inherit system version; };
+                  inherit system version;
                 }
             );
         in
-        builtins.listToAttrs
-          (findPackages
-            (filterPlugins
-              (parseVersions
-                (removeComments
-                  (fileLines versionsFile)))));
+        findPackages (filterPlugins versions);
 
       templates = {
         default = {

tests/lib_test.nix

@@ -2,30 +2,12 @@ let
   lib = (builtins.getFlake (builtins.toString ./..)).lib;
 in
 [
+  # comments
   {
-    name = "Ignores comment lines";
-    actual = lib.packagesFromVersionsFile {
-      versionsFile = builtins.toFile ".tool-versions" ''
-        # This is a comment
-        python 3.12.0
-        # This is another comment
-        terraform 1.6.3
-      '';
-      plugins = {
-        python = {
-          hasVersion = _: true;
-          packageFromVersion = { version, ... }: version;
-        };
-        terraform = {
-          hasVersion = _: true;
-          packageFromVersion = { version, ... }: version;
-        };
-      };
-    };
-    expected = { python = "3.12.0"; terraform = "1.6.3"; };
-  }
-  {
-    name = "Ignores inline comments";
+    name = ''
+      When versionsFile contain comments, then it ignores those during the
+      parsing
+    '';
     actual = lib.packagesFromVersionsFile {
       versionsFile = builtins.toFile ".tool-versions" ''
         # This is a comment
@@ -48,14 +30,8 @@ in
   # skipMissingPlugins = false
   {
     name = ''
-      Given:
-        - A versions file referencing some plugins
-        - A set of plugins matching only one of them
-        - A feature flag to skip missing plugins
-      When:
-        - The matching plugin provides a package for the requested version
-      Then:
-        - Returns a set with the retrieved package
+      When skipMissingPlugins is enabled and some plugins are missing, then
+      returns packages only for the ones matching
     '';
     actual = lib.packagesFromVersionsFile {
       versionsFile = builtins.toFile ".tool-versions" ''
@@ -74,15 +50,8 @@ in
   }
   {
     name = ''
-      Given:
-        - A versions file referencing some plugins
-        - A set of plugins matching only one of them
-        - A feature flag to skip missing plugins
-      When:
-        - The matching plugin does not provide a package for the requested
-          version
-      Then:
-        - Throws an error
+      When skipMissingPlugins is enabled and all plugins are provided, then it
+      returns all the packages
     '';
     actual = builtins.tryEval (
       (lib.packagesFromVersionsFile {
@@ -96,20 +65,14 @@ in
           };
         };
         skipMissingPlugins = true;
-      })
+      }).python
     );
     expected = { success = false; value = false; };
   }
   {
     name = ''
-      Given:
-        - A versions file referencing some plugins
-        - A set of empty plugins
-        - A feature flag to skip missing plugins
-      When:
-        - There are no plugins available
-      Then:
-        - Returns an empty set
+      When skipMissingPlugins is enabled and no plugins are provided, then
+      returns an empty set
     '';
     actual = lib.packagesFromVersionsFile {
       versionsFile = builtins.toFile ".tool-versions" ''
@@ -123,13 +86,8 @@ in
   # skipMissingPlugins = false
   {
     name = ''
-      Given:
-        - A versions file referencing some plugins
-        - A set of plugins matching all of them
-      When:
-        - The matching plugins provide packages for the requested versions
-      Then:
-        - Returns a set with the retrieved packages
+      When skipMissingPlugins is disabled and all plugins are provided, then
+      returns all packages
     '';
     actual = lib.packagesFromVersionsFile {
       versionsFile = builtins.toFile ".tool-versions" ''
@@ -149,39 +107,30 @@ in
     };
     expected = { python = "3.12.0"; terraform = "1.6.3"; };
   }
+  # hasVersions
   {
     name = ''
-      Given:
-        - A versions file referencing some plugins
-        - A set of plugins matching all of them
-      When:
-        - The matching plugin does not provide a package for the requested
-          version
-      Then:
-        - Throws an error
+      When the provided plugin does not contain the requested version, then
+      throws an error
     '';
-    actual = builtins.tryEval (lib.packagesFromVersionsFile {
-      versionsFile = builtins.toFile ".tool-versions" ''
-        python 3.12.0
-      '';
-      plugins = {
-        python = {
-          hasVersion = _: false;
-          packageFromVersion = { version, ... }: version;
+    actual = builtins.tryEval (
+      (lib.packagesFromVersionsFile {
+        versionsFile = builtins.toFile ".tool-versions" ''
+          python 3.12.0
+        '';
+        plugins = {
+          python = {
+            hasVersion = _: false;
+            packageFromVersion = { version, ... }: version;
+          };
         };
-      };
-    });
+      }).python
+    );
     expected = { success = false; value = false; };
   }
   {
     name = ''
-      Given:
-        - A versions file referencing some plugins
-        - A set of empty plugins
-      When:
-        - There are no plugins available
-      Then:
-        - Throws an error
+      When no plugins are provided, then throws an error
     '';
     actual = builtins.tryEval (lib.packagesFromVersionsFile {
       versionsFile = builtins.toFile ".tool-versions" ''

tests/version_files_test.nix

@@ -0,0 +1,89 @@
+let
+  lib = (builtins.getFlake (builtins.toString ./..)).lib;
+in
+[
+  {
+    name = ''
+      When neither versionsFile nor legacyVersionFiles are provided, then
+      throws an error
+    '';
+    actual = builtins.tryEval (lib.packagesFromVersionsFile { });
+    expected = { success = false; value = false; };
+  }
+  {
+    name = ''
+      When only legacyVersionFiles is provided, then returns the package
+      matching the requested version
+    '';
+    actual = lib.packagesFromVersionsFile {
+      legacyVersionFiles = {
+        python = builtins.toFile ".python-version" ''
+          3.12.0
+        '';
+      };
+      plugins = {
+        python = {
+          hasVersion = _: true;
+          packageFromVersion = { version, ... }: version;
+        };
+      };
+    };
+    expected = { python = "3.12.0"; };
+  }
+  {
+    name = ''
+      When both versionsFile and legacyVersionFiles are provided and the
+      plugins does not overlap, then returns packages specified in both files
+    '';
+    actual = lib.packagesFromVersionsFile {
+      versionsFile = builtins.toFile ".tool-versions" ''
+        terraform 1.6.3
+      '';
+      legacyVersionFiles = {
+        python = builtins.toFile ".python-version" ''
+          3.12.0
+        '';
+      };
+      plugins = {
+        python = {
+          hasVersion = _: true;
+          packageFromVersion = { version, ... }: version;
+        };
+        terraform = {
+          hasVersion = _: true;
+          packageFromVersion = { version, ... }: version;
+        };
+      };
+    };
+    expected = { python = "3.12.0"; terraform = "1.6.3"; };
+  }
+  {
+    name = ''
+      When both versionsFile and legacyVersionFiles are provided and the
+      plugins overlap, then the version of the tool coming from the legacy file
+      takes more precedence
+    '';
+    actual = lib.packagesFromVersionsFile {
+      versionsFile = builtins.toFile ".tool-versions" ''
+        python 2.7.6
+        terraform 1.6.3
+      '';
+      legacyVersionFiles = {
+        python = builtins.toFile ".python-version" ''
+          3.12.0
+        '';
+      };
+      plugins = {
+        python = {
+          hasVersion = _: true;
+          packageFromVersion = { version, ... }: version;
+        };
+        terraform = {
+          hasVersion = _: true;
+          packageFromVersion = { version, ... }: version;
+        };
+      };
+    };
+    expected = { python = "3.12.0"; terraform = "1.6.3"; };
+  }
+]