Add regression test that all imports keep being explicit.

Author: GunnarFarneback

test/runtests.jl

@@ -1,9 +1,22 @@
 import RegistryTools
 using Test: @testset, @test
+import Pkg
 
 @testset "RegistryTools" begin
 
 include("regedit.jl")
 include("compress.jl")
 
+# ExplicitImports does not support as old Julia versions as RegistryTools does.
+# Change this to a regular test dependency when it becomes possible, i.e.
+# when pre-1.7 support is dropped.
+if VERSION >= v"1.7"
+Pkg.add(name = "ExplicitImports", uuid = "7d51a73a-1435-4ff3-83d9-f097790105c7", preserve=Pkg.PRESERVE_ALL)
+using ExplicitImports: check_no_implicit_imports, check_no_stale_explicit_imports
+@testset "ExplicitImports" begin
+    @test isnothing(check_no_implicit_imports(RegistryTools))
+    @test isnothing(check_no_stale_explicit_imports(RegistryTools))
+end
+end
+
 end