Fix/93 moo meta no moose

.github/workflows/testsuite.yml

@@ -94,3 +94,60 @@ jobs:
       - run: perl Build.PL
       - run: ./Build
       - run: ./Build test
+
+  # Exercises every optional-OO-dependency permutation -- the full
+  # {Moo, Moose, Mouse} cross-product (8 profiles) -- so each OO system is
+  # tested in isolation and in combination. Uses a clean setup-perl Perl
+  # (NOT the perl-tester container, which preloads Moose and would defeat the
+  # `none`/`moo`/`mouse` profiles) and installs each profile's modules
+  # explicitly (no --with-recommends). The `moo` profile -- Moo present, Moose
+  # absent -- is the configuration that reproduces GH #93. Support deps are
+  # paired with the systems whose tests need them: Class::Load + Test::Exception
+  # for the Moose tests (t/moose_around.t needs Class::Load), Test::Exception
+  # for t/mouse_basic.t. Tests for an absent system skip_all, so a profile only
+  # installs what it actually exercises.
+  oo-deps:
+    name: oo-deps (${{ matrix.profile.name }})
+    env:
+      PERL_USE_UNSAFE_INC: 0
+      AUTOMATED_TESTING: 1
+
+    runs-on: ubuntu-latest
+
+    needs: [ubuntu]
+
+    strategy:
+      fail-fast: false
+      matrix:
+        profile:
+          - name: none
+            install: ""
+          - name: moo
+            install: "Moo"
+          - name: moose
+            install: "Moose Class::Load Test::Exception"
+          - name: mouse
+            install: "Mouse Test::Exception"
+          - name: moo+moose
+            install: "Moo Moose Class::Load Test::Exception"
+          - name: moo+mouse
+            install: "Moo Mouse Test::Exception"
+          - name: moose+mouse
+            install: "Moose Mouse Class::Load Test::Exception"
+          - name: all
+            install: "Moo Moose Mouse Class::Load Test::Exception"
+
+    steps:
+      - uses: actions/checkout@v6
+      - uses: shogo82148/actions-setup-perl@v1
+      - run: perl -V
+      # Required deps only -- NO --with-recommends, so the optional OO modules
+      # are controlled per-profile below.
+      - name: install required dependencies
+        run: cpanm --installdeps --notest .
+      - name: install OO profile dependencies
+        if: matrix.profile.install != ''
+        run: cpanm --notest ${{ matrix.profile.install }}
+      - run: perl Build.PL
+      - run: ./Build
+      - run: ./Build test

.gitignore

@@ -39,3 +39,4 @@ pm_to_blib
 
 Test-MockModule-*
 docs/superpowers
+.tickets/

Build.PL

@@ -47,8 +47,9 @@ my $builder = $class->new(
 		'Test::Warnings'      => 0,
 	},
 	# Moose, Mouse, Class::Load and Test::Exception are exercised ONLY by the
-	# t/moose_*.t and t/mouse_*.t MOP-integration tests added for GH #55. Each
-	# of those files opens with `eval { require Moose } or plan skip_all`, so
+	# t/moose_*.t and t/mouse_*.t MOP-integration tests added for GH #55, and
+	# Moo only by the t/moo_*.t tests added for GH #93. Each of those files
+	# opens with an `eval { require <Module> } or plan skip_all`, so
 	# the suite passes cleanly without them. They are therefore OPTIONAL, not
 	# required: declaring them as `recommends` keeps a plain
 	# `cpanm Test::MockModule` from dragging in two full Perl OO systems (GH #90).
@@ -65,6 +66,7 @@ my $builder = $class->new(
 		'Class::Load'         => 0,
 		'Moose'               => 0,
 		'Mouse'               => 0,
+		'Moo'                 => 0,
 	},
 
 	add_to_cleanup => [

Changes

@@ -1,3 +1,8 @@
+## Unreleased
+
+## What's Changed
+* fix(GH #93): don't require Moose when mocking a Moo class — `_meta_for` no longer triggers Moo's lazy Moose metaclass inflation
+
 ## 0.185.2 — 2026-05-29
 
 ## What's Changed

lib/Test/MockModule.pm

@@ -558,6 +558,11 @@ sub _meta_for {
 	return unless $package->can('meta');
 	my $meta = eval { $package->meta };
 	return unless ref $meta;
+	# Moo's ->meta returns a Moo::HandleMoose::FakeMetaClass whose ->isa lazily
+	# inflates a real Moose metaclass -- which throws when Moose isn't installed.
+	# Match it by exact ref (not ->isa) BEFORE the isa checks so inflation never
+	# fires; Moo classes fall back to plain symbol-table mocking. (GH #93)
+	return if ref($meta) eq 'Moo::HandleMoose::FakeMetaClass';
 	return $meta if $meta->isa('Class::MOP::Class');   # Moose
 	return $meta if $meta->isa('Mouse::Meta::Class');  # Mouse
 	return;

t/moo_basic.t

@@ -0,0 +1,52 @@
+use strict;
+use warnings;
+use Test::More;
+
+BEGIN {
+    eval { require Moo; 1 } or plan skip_all => "Moo not installed";
+}
+
+use Test::MockModule;
+
+{
+    package Issue93::MooClass; ## no critic (Modules::RequireFilenameMatchesPackage)
+    use Moo;
+    has answer => (is => 'ro', default => 42);
+    sub greet { 'real_greet' }
+}
+
+{
+    package Issue93::MooParent; ## no critic (Modules::RequireFilenameMatchesPackage)
+    use Moo;
+    sub bar { 'parent_bar' }
+}
+{
+    package Issue93::MooChild; ## no critic (Modules::RequireFilenameMatchesPackage)
+    use Moo;
+    extends 'Issue93::MooParent';
+}
+
+# Basic mock-and-call
+my $mock = Test::MockModule->new('Issue93::MooClass');
+$mock->mock( greet => sub { 'mocked_greet' } );
+is(Issue93::MooClass->new->greet, 'mocked_greet', "Moo mock visible");
+is(Issue93::MooClass->new->answer, 42, "Moo accessor unaffected by mock");
+
+$mock->unmock('greet');
+is(Issue93::MooClass->new->greet, 'real_greet', "Moo unmock restores original");
+
+# Moo-generated accessors are ordinary subs in the symbol table, so plain
+# replacement mocking must work on them too.
+$mock->mock( answer => sub { 99 } );
+is(Issue93::MooClass->new->answer, 99, "Moo accessor mock visible");
+$mock->unmock('answer');
+is(Issue93::MooClass->new->answer, 42, "Moo accessor unmock restores original");
+
+# Inherited method mock-and-restore
+my $imock = Test::MockModule->new('Issue93::MooChild');
+$imock->mock( bar => sub { 'mocked_bar' } );
+is(Issue93::MooChild->bar, 'mocked_bar', "Moo inherited mock visible");
+$imock->unmock('bar');
+is(Issue93::MooChild->bar, 'parent_bar', "Moo unmock falls through to parent");
+
+done_testing;

t/moo_meta_for.t

@@ -0,0 +1,36 @@
+use strict;
+use warnings;
+use Test::More;
+
+BEGIN {
+    eval { require Moo; 1 } or plan skip_all => "Moo not installed";
+}
+
+use Test::MockModule;
+
+# Plain (non-Moo) package
+{
+    package PlainPkg; ## no critic (Modules::RequireFilenameMatchesPackage)
+    sub new { bless {}, shift }
+}
+
+# Moo package
+{
+    package MooPkg; ## no critic (Modules::RequireFilenameMatchesPackage)
+    use Moo;
+    has answer => (is => 'ro', default => 42);
+    sub greet { 'real_greet' }
+}
+
+# A Moo class must NOT be treated as a Moose/Mouse MOP class: _meta_for
+# returns undef so mocking falls back to plain symbol-table replacement.
+# Pre-fix this either returns a truthy Moo::HandleMoose::FakeMetaClass
+# (Moose installed) or throws inside Moo::HandleMoose (Moose absent).
+is(Test::MockModule::_meta_for('MooPkg'), undef, "Moo package returns undef meta");
+
+is(Test::MockModule::_meta_for('PlainPkg'), undef, "plain package returns undef");
+is(Test::MockModule::_meta_for(undef), undef, "undef package returns undef");
+is(Test::MockModule::_meta_for(''), undef, "empty package returns undef");
+is(Test::MockModule::_meta_for('Does::Not::Exist'), undef, "nonexistent package returns undef");
+
+done_testing;