add option to skip outputting empty import lists in use statements

Changes

@@ -1,6 +1,9 @@
 Revision history for App-perlimports
 
 {{$NEXT}}
+    - Add experimental --skip-empty-imports flag, to allow following style
+      guides that do not want an empty `qw()` import list in use statements.
+      (GH#118) (Thomas Lamprecht)
 
 0.000057  2025-04-30 12:12:23Z
     - Update test expectations for MooseX::Types::Moose 0.51 (GH#122) (Olaf

lib/App/perlimports/CLI.pm

@@ -190,6 +190,11 @@ sub _build_args {
             'Pad imports: qw( foo bar ) vs qw(foo bar). Defaults to true',
         ],
         [],
+        [
+            'skip-empty-imports!',
+            'Skip empty imports: Foo qw(); vs Foo;. Defaults to false',
+        ],
+        [],
         [
             'read-stdin',
             'Read statements to process from STDIN rather than the supplied file.',
@@ -266,6 +271,7 @@ sub _build_config {
         log_level
         never_export_modules_filename
         padding
+        skip_empty_imports
         preserve_duplicates
         preserve_unused
         tidy_whitespace
@@ -450,6 +456,7 @@ sub run {
         lint                => $self->_lint,
         logger              => $logger,
         padding             => $self->_config->padding,
+        skip_empty_imports  => $self->_config->skip_empty_imports,
         preserve_duplicates => $self->_config->preserve_duplicates,
         preserve_unused     => $self->_config->preserve_unused,
         tidy_whitespace     => $self->_config->tidy_whitespace,

lib/App/perlimports/Config.pm

@@ -111,6 +111,13 @@ has padding => (
     default => 1,
 );
 
+has skip_empty_imports => (
+    is      => 'ro',
+    isa     => Bool,
+    lazy    => 1,
+    default => 0,
+);
+
 has preserve_duplicates => (
     is      => 'ro',
     isa     => Bool,
@@ -230,3 +237,4 @@ padding                         = true
 preserve_duplicates             = false
 preserve_unused                 = false
 tidy_whitespace                 = true
+skip_empty_imports              = false

lib/App/perlimports/Document.pm

@@ -170,6 +170,13 @@ has _padding => (
     default  => 1,
 );
 
+has _skip_empty_imports => (
+    is       => 'ro',
+    isa      => Bool,
+    init_arg => 'skip_empty_imports',
+    default  => 0,
+);
+
 has ppi_document => (
     is      => 'ro',
     isa     => Object,
@@ -897,7 +904,8 @@ INCLUDE:
             logger           => $self->logger,
             original_imports => $self->original_imports->{ $include->module },
             pad_imports      => $self->_padding,
-            tidy_whitespace  => $self->_tidy_whitespace,
+            skip_empty_imports => $self->_skip_empty_imports,
+            tidy_whitespace    => $self->_tidy_whitespace,
         );
         my $elem;
         try {

lib/App/perlimports/Include.pm

@@ -128,6 +128,13 @@ has _pad_imports => (
     default  => sub { 1 },
 );
 
+has _skip_empty_imports => (
+    is       => 'ro',
+    isa      => Bool,
+    init_arg => 'skip_empty_imports',
+    default  => sub { 0 },
+);
+
 has _tidy_whitespace => (
     is       => 'ro',
     isa      => Bool,
@@ -464,11 +471,10 @@ sub _build_formatted_ppi_statement {
     if (   $self->_will_never_export
         || $self->_is_translatable
         || !@{ $self->_imports } ) {
+        my $template
+            = $self->_skip_empty_imports() ? 'use %s%s;' : 'use %s%s ();';
         return $self->_maybe_get_new_include(
-            sprintf(
-                'use %s%s ();', $self->module_name, $maybe_module_version
-            )
-        );
+            sprintf( $template, $self->module_name, $maybe_module_version ) );
     }
 
     my $statement;

script/perlimports

@@ -425,6 +425,21 @@ parentheses.
     # --no-padding
     use Foo qw(bar baz);
 
+=head2 --[no-]skip-empty-imports
+
+C<--skip-empty-imports> is disabled by default. This means that empty import
+statements will always get added to use statements. This setting skips adding
+a import stanza if there is nothing to import.
+
+    # --no-skip-empty-imports
+    use Foo qw();
+
+The C<--skip-empty-imports> arg allows you to disable outputting an empty
+import list.
+
+    # --skip-empty-imports
+    use Foo;
+
 =head2 --[no-]tidy-whitespace
 
 C<--tidy-whitespace> is enabled by default. This means that use statements will

t/cli-args.t

@@ -39,6 +39,7 @@ EOF
         '--log-level'    => 'info',
         '--no-cache',
         '--no-padding',
+        '--skip-empty-imports',
         '--no-preserve-duplicates',
         '--no-preserve-unused',
         '--no-tidy-whitespace',
@@ -70,6 +71,7 @@ EOF
         'never_export'
     );
     is( $c->padding,             0, 'padding' );
+    is( $c->skip_empty_imports,  1, 'skip_empty_imports' );
     is( $c->preserve_duplicates, 0, 'preserve_duplicates' );
     is( $c->tidy_whitespace,     0, 'tidy_whitespace' );
 };

t/cli.t

@@ -454,6 +454,50 @@ EOF
     is( $stderr, q{},       'no STDERR' );
 };
 
+subtest '--skip-empty-imports' => sub {
+    my $expected = <<'EOF';
+use strict;
+use warnings;
+
+use Carp;
+use Data::Dumper;
+use POSIX;
+EOF
+
+    local @ARGV = (
+        '--no-config-file',
+        '--skip-empty-imports',
+        '-f' => 'test-data/original-imports.pl',
+    );
+    my $cli = App::perlimports::CLI->new;
+    my ( $stdout, $stderr ) = capture { $cli->run };
+    is( $stderr, q{},       'no STDERR' );
+    is( $stdout, $expected, 'stdout' );
+    is( $stderr, q{},       'no STDERR' );
+};
+
+subtest '--no-skip-empty-imports' => sub {
+    my $expected = <<'EOF';
+use strict;
+use warnings;
+
+use Carp ();
+use Data::Dumper ();
+use POSIX ();
+EOF
+
+    local @ARGV = (
+        '--no-config-file',
+        '--no-skip-empty-imports',
+        '-f' => 'test-data/original-imports.pl',
+    );
+    my $cli = App::perlimports::CLI->new;
+    my ( $stdout, $stderr ) = capture { $cli->run };
+    is( $stderr, q{},       'no STDERR' );
+    is( $stdout, $expected, 'stdout' );
+    is( $stderr, q{},       'no STDERR' );
+};
+
 subtest '--stdout' => sub {
     my $expected = <<'EOF';
 use strict;