From 38f764190ff8f8264d6b729ea40fc1d726f5c765 Mon Sep 17 00:00:00 2001
From: Olivier Cots <olivier.cots@irit.fr>
Date: Thu, 23 Jul 2026 12:04:41 +0200
Subject: [PATCH] Fix: Tip line in show(MIME"text/plain", strategy) now shows
 parameterized type name
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The Tip message in Base.show(io, MIME"text/plain", strategy) used
type_name (just nameof(T)) instead of display_name (which includes the
parameter, e.g. DifferentiationInterface{GPU}). This caused the Tip to
always show describe(DifferentiationInterface) even for parameterized
instances like DifferentiationInterface{GPU}.

Changed type_name to display_name in the Tip println call. Updated the
docstring example to show both non-parameterized and parameterized cases.

Added tests with a fake parameterized strategy (CovFakeParamStrategy{P})
to verify:
- Non-parameterized: Tip shows describe(CovFakeStrategy) without {…}
- Parameterized: Tip shows describe(CovFakeParamStrategy{CPU}) with {CPU}
---
 src/Strategies/contract/abstract_strategy.jl  |  8 ++-
 .../test_coverage_abstract_strategy.jl        | 49 +++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/src/Strategies/contract/abstract_strategy.jl b/src/Strategies/contract/abstract_strategy.jl
index 998d1ffe..3c1836e1 100644
--- a/src/Strategies/contract/abstract_strategy.jl
+++ b/src/Strategies/contract/abstract_strategy.jl
@@ -465,6 +465,12 @@ FakeSolver (instance, id: :fake_solver)
 ├─ max_iter = 1000  [default]
 └─ tol = 1.0e-8  [default]
 Tip: use describe(FakeSolver) to see all available options.
+
+julia> FakeSolver{CPU}()
+FakeSolver{CPU} (instance, id: :fake_solver)
+├─ max_iter = 1000  [default]
+└─ tol = 1.0e-8  [default]
+Tip: use describe(FakeSolver{CPU}) to see all available options.
 ```
 
 See also: [`CTBase.Strategies.describe`](@ref), [`CTBase.Strategies.options`](@ref)
@@ -520,7 +526,7 @@ function Base.show(io::IO, ::MIME"text/plain", strategy::T) where {T<:AbstractSt
         io,
         fmt.label,
         "Tip: use describe(",
-        type_name,
+        display_name,
         ") to see all available options.",
         fmt.reset,
     )
diff --git a/test/suite/strategies/test_coverage_abstract_strategy.jl b/test/suite/strategies/test_coverage_abstract_strategy.jl
index 8f77de8b..9c3ee0ec 100644
--- a/test/suite/strategies/test_coverage_abstract_strategy.jl
+++ b/test/suite/strategies/test_coverage_abstract_strategy.jl
@@ -70,6 +70,25 @@ end
 
 Strategies.options(s::CovSingleOptStrategy) = s.options
 
+# Fake parameterized strategy for testing Tip display with parameter
+struct CovFakeParamStrategy{P} <: Strategies.AbstractStrategy
+    options::Strategies.StrategyOptions
+end
+
+Strategies.id(::Type{<:CovFakeParamStrategy}) = :cov_fake_param
+Strategies.default_parameter(::Type{<:CovFakeParamStrategy}) = Strategies.CPU
+Strategies.parameter(::Type{<:CovFakeParamStrategy{P}}) where {P} = P
+
+function Strategies.metadata(::Type{<:CovFakeParamStrategy{P}}) where {P}
+    return Strategies.StrategyMetadata(
+        Options.OptionDefinition(;
+            name=:max_iter, type=Int, default=100, description="Maximum iterations"
+        ),
+    )
+end
+
+Strategies.options(s::CovFakeParamStrategy) = s.options
+
 # ============================================================================
 # Test function
 # ============================================================================
@@ -134,6 +153,36 @@ function test_coverage_abstract_strategy()
             Test.@test occursin("value", output)
         end
 
+        Test.@testset "show(io, MIME text/plain) - Tip shows type name without parameter" begin
+            opts = Strategies.StrategyOptions(
+                max_iter=Options.OptionValue(200, :user),
+                tol=Options.OptionValue(1e-8, :default),
+            )
+            strategy = CovFakeStrategy(opts)
+
+            buf = IOBuffer()
+            show(buf, MIME("text/plain"), strategy)
+            output = String(take!(buf))
+
+            Test.@test occursin("Tip: use describe(CovFakeStrategy)", output)
+            Test.@test !occursin("CovFakeStrategy{", output)
+        end
+
+        Test.@testset "show(io, MIME text/plain) - Tip shows parameterized type name" begin
+            opts = Strategies.StrategyOptions(
+                max_iter=Options.OptionValue(100, :default),
+            )
+            strategy = CovFakeParamStrategy{Strategies.CPU}(opts)
+
+            buf = IOBuffer()
+            show(buf, MIME("text/plain"), strategy)
+            output = String(take!(buf))
+
+            Test.@test occursin(
+                "Tip: use describe(CovFakeParamStrategy{CPU})", output
+            )
+        end
+
         # ====================================================================
         # UNIT TESTS - show(io, strategy) - compact display
         # ====================================================================