Return a callable object from install()

Project.toml

@@ -1,7 +1,7 @@
 name = "PkgAuthentication"
 uuid = "4722fa14-9d28-45f9-a1e2-a38605bd88f0"
 authors = ["Sebastian Pfitzner", "contributors"]
-version = "2.2.3"
+version = "2.3.0"
 
 [deps]
 Downloads = "f43a241f-c20a-4ad4-852c-f6b1247861c6"

src/PkgAuthentication.jl

@@ -835,7 +835,7 @@ function open_browser(url::AbstractString)
 end
 
 """
-    install(server::AbstractString; maxcount = 3)
+    install(server::AbstractString; maxcount = 3) -> PkgAuthentication.Uninstall
 
 Install Pkg authentication hooks for the Pkg server specified by `server`. Also
 sets the `$(pkg_server_env_var_name)` environment variable to `server`.
@@ -862,7 +862,7 @@ function install(server::AbstractString; maxcount::Integer=3)
 end
 
 """
-    install(; maxcount = 3)
+    install(; maxcount = 3) -> PkgAuthentication.Uninstall
 
 Install Pkg authentication hooks for the Pkg server specified in the `$(pkg_server_env_var_name)`
 environment variable.
@@ -872,6 +872,8 @@ must be set to the URL of a valid Pkg server.
 
 `maxcount` determines the number of retries.
 
+You can call the returned object (no arguments) to uninstall the Pkg authentication hooks.
+
 !!! compat "Julia 1.4"
     Pkg authentication hooks require at least Julia 1.4. On earlier versions, this
     method will instead force authentication immediately.
@@ -880,8 +882,10 @@ must be set to the URL of a valid Pkg server.
 
 ```julia
 julia> PkgAuthentication.install()
+PkgAuthentication.Uninstall (call this object to remove Pkg hooks)
 
 julia> PkgAuthentication.install(; maxcount = 5)
+PkgAuthentication.Uninstall (call this object to remove Pkg hooks)
 ```
 """
 function install(; maxcount::Integer=3)
@@ -891,12 +895,15 @@ function install(; maxcount::Integer=3)
     _assert_pkg_server_env_var_is_set()
     server = String(pkg_server())
     auth_handler = generate_auth_handler(maxcount)
-    @static if PkgAuthentication.is_new_auth_mechanism()
+    uninstall_hook = @static if PkgAuthentication.is_new_auth_mechanism()
         Pkg.PlatformEngines.register_auth_error_handler(server, auth_handler)
     else
         # old Julia versions don't support auth hooks, so let's authenticate now and be done with it
         authenticate(server)
+        # the returned Uninstall will be a silent no-op
+        nothing
     end
+    return Uninstall(uninstall_hook)
 end
 
 function generate_auth_handler(maxcount::Integer)
@@ -921,6 +928,27 @@ function generate_auth_handler(maxcount::Integer)
     return auth_handler
 end
 
+"""
+    struct Uninstall
+
+Wrapper around the closure returned by `Pkg.PlatformEngines.register_auth_error_handler`.
+Calling this object will remove the Pkg authentication hooks.
+
+```julia
+julia> uninstall = PkgAuthentication.install()
+PkgAuthentication.Uninstall (call this object to remove Pkg hooks)
+
+julia> uninstall()
+```
+"""
+struct Uninstall
+    f::Union{Base.Callable, Nothing}
+end
+(c::Uninstall)() = isnothing(c.f) ? nothing : c.f()
+function Base.show(io::IO, ::MIME"text/plain", ::Uninstall)
+    print(io, "PkgAuthentication.Uninstall (call this object to remove Pkg hooks)")
+end
+
 include("precompile.jl")
 
 end # module

test/tests.jl

@@ -136,16 +136,31 @@ end
     delete_token()
 
     result = PkgAuthentication.install(test_pkg_server)
+    @test result isa PkgAuthentication.Uninstall
     @static if PkgAuthentication.is_new_auth_mechanism()
         # On Julia 1.4+, the return value of `PkgAuthentication.install` will be
         # the return value from the `Pkg.PlatformEngines.register_auth_error_handler`
         # call. `Pkg.PlatformEngines.register_auth_error_handler` returns a zero-arg function
         # that can be called to deregister the handler.
-        @test result isa Function
+        @test result.f isa Function
     else
         # On Julia <1.4, the return value of `PkgAuthentication.install` will be
         # the return value from the `PkgAuthentication.authenticate` call.
-        @test result isa PkgAuthentication.Success
+        @test isnothing(result.f)
+    end
+
+    @testset "PkgAuthentication.Uninstall" begin
+        let u = PkgAuthentication.Uninstall(nothing)
+            @test u() === nothing
+        end
+        let count = 1
+            u = PkgAuthentication.Uninstall(() -> (count += 1; nothing))
+            @test count == 1
+            @test u() === nothing
+            @test count == 2
+            @test u() === nothing
+            @test count == 3
+        end
     end
 end