Fix weak dep, which is a test dep for merged projects (#40)

* fix weak dep, which is a test dep

* use julia v1.10

* try to fix julia version mismatch error

* Revert "try to fix julia version mismatch error"

This reverts commit 29781e9.

* make VERSION the default for julia_version

* clarify README

Author: JoshuaLampert

README.md

@@ -51,8 +51,8 @@ minimal versions and fail if your compat bounds are too low.
     mode: 'alldeps'
 
     # Julia version to use with resolver (requires Julia 1.9+)
-    # Default: '1.10'
-    julia_version: '1.10'
+    # Default: '1' (converted to current runtime Julia major.minor)
+    julia_version: '1'
 ```
 
 ## Example
@@ -86,6 +86,9 @@ before `julia-buildpkg` so that Resolver.jl creates a Manifest.toml with minimal
 
 In this example, we test both `deps` (direct dependencies only) and `alldeps` (deps + weakdeps) scenarios.
 
+When possible, run the action on the same Julia version that you pass as `julia_version`.
+Cross-runtime resolution may fail; matching runtime and target version is recommended and the default for `julia_version`.
+
 ## Downgrade Modes
 
 - **`deps`**: Minimize only your direct dependencies (recommended for most packages)

action.yml

@@ -11,8 +11,8 @@ inputs:
     description: 'Downgrade mode: deps (direct dependencies), alldeps (deps + weakdeps), weakdeps (only weakdeps), forcedeps (deps with strict lower bound verification)'
     default: 'alldeps'
   julia_version:
-    description: 'Julia version to use with resolver (default: 1.10)'
-    default: '1.10'
+    description: 'Julia version to use with resolver (default: 1, i.e. current runtime Julia major.minor)'
+    default: '1'
 runs:
   using: "composite"
   steps:

downgrade.jl

@@ -3,15 +3,20 @@ using TOML
 ignore_pkgs = filter(!isempty, map(strip, split(ARGS[1], ",")))
 dirs = filter(!isempty, map(strip, split(ARGS[2], ",")))
 mode = length(ARGS) >= 3 ? ARGS[3] : "deps"
-julia_version = length(ARGS) >= 4 ? ARGS[4] : "1.10"
+current_julia_minor = string(VERSION.major, ".", VERSION.minor)
+julia_version = length(ARGS) >= 4 ? ARGS[4] : current_julia_minor
 
 # Convert "1" to the current running Julia version (e.g., "1.12" for Julia 1.12.3)
 # This ensures the resolved manifest matches the Julia version that will read it
 if julia_version == "1"
-    julia_version = string(VERSION.major, ".", VERSION.minor)
+    julia_version = current_julia_minor
     @info "Converted julia_version \"1\" to \"$julia_version\" (current Julia version)"
 end
 
+if julia_version != current_julia_minor
+    @warn "Requested julia_version=$julia_version differs from current runtime Julia $current_julia_minor. Cross-runtime mode may fail."
+end
+
 valid_modes = ["deps", "alldeps", "weakdeps", "forcedeps"]
 mode in valid_modes || error("mode must be one of: $(join(valid_modes, ", "))")
 
@@ -137,17 +142,31 @@ function create_merged_project(main_project_file::String, test_project_file::Str
     delete!(merged, "workspace")
 
     # Merge deps from test project (excluding source packages)
+    # If a package is weak in main but strong in test, promote it to strong
+    # in the merged project by removing it from weakdeps.
     test_deps = get(test_project, "deps", Dict())
     if !haskey(merged, "deps")
         merged["deps"] = Dict{String, Any}()
     end
     for (pkg, uuid) in test_deps
-        if pkg ∉ source_pkgs && !haskey(merged["deps"], pkg)
-            merged["deps"][pkg] = uuid
-            @info "Adding test dependency to merged project: $pkg"
+        if pkg ∉ source_pkgs
+            if !haskey(merged["deps"], pkg)
+                merged["deps"][pkg] = uuid
+                @info "Adding test dependency to merged project: $pkg"
+            end
+
+            if haskey(merged, "weakdeps") && haskey(merged["weakdeps"], pkg)
+                delete!(merged["weakdeps"], pkg)
+                @info "Promoting $pkg from weakdep to dependency in merged project"
+            end
         end
     end
 
+    # Remove empty [weakdeps] section after promotions
+    if haskey(merged, "weakdeps") && isempty(merged["weakdeps"])
+        delete!(merged, "weakdeps")
+    end
+
     # Merge compat entries from test project
     test_compat = get(test_project, "compat", Dict())
     if !haskey(merged, "compat")

test/runtests.jl

@@ -107,7 +107,7 @@ downgrade_jl = joinpath(dirname(@__DIR__), "downgrade.jl")
 
                 # Run the downgrade script with forcedeps mode - should fail
                 @test_throws ProcessFailedException run(
-                    `$(Base.julia_cmd()) $downgrade_jl "" "." "forcedeps" "1.10"`,
+                    `$(Base.julia_cmd()) $downgrade_jl "" "." "forcedeps"`,
                 )
             end
         end
@@ -300,4 +300,60 @@ downgrade_jl = joinpath(dirname(@__DIR__), "downgrade.jl")
             end
         end
     end
+
+    @testset "merged resolution promotes weakdeps used by tests" begin
+        mktempdir() do dir
+            cd(dir) do
+                # Main project has JuMP as weakdep
+                main_toml = """
+                name = "TestPackage"
+                uuid = "598b003f-0677-49cf-8d2a-39b1658b755a"
+                version = "0.1.0"
+
+                [deps]
+
+                [weakdeps]
+                JuMP = "4076af6c-e467-56ae-b986-b466b2749572"
+
+                [extensions]
+                JuMPExt = "JuMP"
+
+                [compat]
+                julia = "1.10"
+                JuMP = "1.28"
+
+                [workspace]
+                projects = ["test"]
+                """
+                write("Project.toml", main_toml)
+
+                mkdir("src")
+                write("src/TestPackage.jl", "module TestPackage\nend\n")
+
+                # Test project requires JuMP as a regular dependency
+                mkdir("test")
+                test_toml = """
+                [deps]
+                TestPackage = "598b003f-0677-49cf-8d2a-39b1658b755a"
+                JuMP = "4076af6c-e467-56ae-b986-b466b2749572"
+
+                [compat]
+                JuMP = "1.28"
+
+                [sources.TestPackage]
+                path = ".."
+                """
+                write("test/Project.toml", test_toml)
+
+                run(`$(Base.julia_cmd()) $downgrade_jl "" ".,test" "forcedeps"`)
+
+                manifest = TOML.parsefile("Manifest.toml")
+                deps = manifest["deps"]
+
+                deps_JuMP = get(deps, "JuMP", [])
+                @test !isempty(deps_JuMP)
+                @test startswith(deps_JuMP[1]["version"], "1.28")
+            end
+        end
+    end
 end