From 6198fc5acbeb15381df75a63f91004c4e6cf3798 Mon Sep 17 00:00:00 2001
From: Herwin <herwinw@users.noreply.github.com>
Date: Mon, 11 Sep 2023 12:47:26 +0200
Subject: [PATCH] Add tests for to_str conversion in Kernel.(s)printf

There is a similar test for IO#printf, but this tests the more generic
case.
---
 core/kernel/printf_spec.rb  |  7 +++++++
 core/kernel/sprintf_spec.rb | 16 ++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/core/kernel/printf_spec.rb b/core/kernel/printf_spec.rb
index d8f93ce429..61bf955c25 100644
--- a/core/kernel/printf_spec.rb
+++ b/core/kernel/printf_spec.rb
@@ -31,6 +31,13 @@
     object.should_receive(:write).with("string")
     Kernel.printf(object, "%s", "string")
   end
+
+  it "calls #to_str to convert the format object to a String" do
+    object = mock('format string')
+    object.should_receive(:to_str).and_return("to_str: %i")
+    $stdout.should_receive(:write).with("to_str: 42")
+    Kernel.printf($stdout, object, 42)
+  end
 end
 
 describe "Kernel.printf" do
diff --git a/core/kernel/sprintf_spec.rb b/core/kernel/sprintf_spec.rb
index 7adf71be76..9ef7f86f16 100644
--- a/core/kernel/sprintf_spec.rb
+++ b/core/kernel/sprintf_spec.rb
@@ -3,6 +3,14 @@
 require_relative 'shared/sprintf'
 require_relative 'shared/sprintf_encoding'
 
+describe :kernel_sprintf_to_str, shared: true do
+  it "calls #to_str to convert the format object to a String" do
+    obj = mock('format string')
+    obj.should_receive(:to_str).and_return("to_str: %i")
+    @method.call(obj, 42).should == "to_str: 42"
+  end
+end
+
 describe "Kernel#sprintf" do
   it_behaves_like :kernel_sprintf, -> format, *args {
     sprintf(format, *args)
@@ -11,6 +19,10 @@
   it_behaves_like :kernel_sprintf_encoding, -> format, *args {
     sprintf(format, *args)
   }
+
+  it_behaves_like :kernel_sprintf_to_str, -> format, *args {
+    sprintf(format, *args)
+  }
 end
 
 describe "Kernel.sprintf" do
@@ -21,4 +33,8 @@
   it_behaves_like :kernel_sprintf_encoding, -> format, *args {
     Kernel.sprintf(format, *args)
   }
+
+  it_behaves_like :kernel_sprintf_to_str, -> format, *args {
+    Kernel.sprintf(format, *args)
+  }
 end