blend env var

.github/workflows/ci.yml

@@ -10,6 +10,8 @@ jobs:
   mix_test:
     name: mix test (Elixir ${{matrix.elixir}} | Erlang/OTP ${{matrix.otp}})
     runs-on: ubuntu-latest
+    env:
+      BLEND: ${{ matrix.blend }}
     strategy:
       fail-fast: false
       matrix:
@@ -49,9 +51,6 @@ jobs:
         with:
           otp-version: ${{matrix.otp}}
           elixir-version: ${{matrix.elixir}}
-      - name: Set lock file from blend
-        if: matrix.blend
-        run: cp blend/${{matrix.blend}}.mix.lock mix.lock
       - name: Update deps
         if: matrix.update_deps
         run: mix deps.update --all
@@ -62,7 +61,9 @@ jobs:
           path: |
               deps
               _build
-          key: ${{ runner.os }}-${{ runner.arch }}-${{ matrix.otp }}-${{ matrix.elixir }}-${{ hashFiles('mix.lock') }}
+              blend/deps
+              blend/_build
+          key: ${{ runner.os }}-${{ runner.arch }}-${{ matrix.otp }}-${{ matrix.elixir }}-${{ matrix.blend }}-${{ hashFiles('mix.lock', 'blend/*.mix.lock') }}
       - name: Install Dependencies
         if: steps.deps-cache.outputs.cache-hit != 'true'
         run: |

blend/premix.exs

@@ -0,0 +1,22 @@
+# This file is autogenerated by blend package.
+#
+# Run `mix blend.premix` to update it's contents after
+# each blend package version update.
+
+maybe_put_env = fn varname, value ->
+  System.put_env(varname, System.get_env(varname, value))
+end
+
+existing_blend = fn name ->
+  Code.eval_file("blend.exs")
+  |> elem(0)
+  |> Map.fetch!(String.to_atom(name))
+end
+
+blend = System.get_env("BLEND")
+
+if blend && String.length(blend) > 0 && existing_blend.(blend) do
+  maybe_put_env.("MIX_LOCKFILE", "blend/#{blend}.mix.lock")
+  maybe_put_env.("MIX_DEPS_PATH", "blend/deps/#{blend}")
+  maybe_put_env.("MIX_BUILD_ROOT", "blend/_build/#{blend}")
+end

mix.exs

@@ -1,3 +1,5 @@
+Code.compile_file("blend/premix.exs")
+
 defmodule Surface.MixProject do
   use Mix.Project
 
@@ -17,6 +19,7 @@ defmodule Surface.MixProject do
       docs: docs(),
       package: package()
     ]
+    |> Keyword.merge(maybe_lockfile_option())
   end
 
   # Run "mix help compile.app" to learn about applications.
@@ -81,4 +84,12 @@ defmodule Surface.MixProject do
   defp catalogues do
     ["priv/catalogue"]
   end
+
+  def maybe_lockfile_option do
+    case System.get_env("MIX_LOCKFILE") do
+      nil -> []
+      "" -> []
+      lockfile -> [lockfile: lockfile]
+    end
+  end
 end