feat: add --collect-coverage-from option to include untested files in coverage

Closes #418

Adds a new --collect-coverage-from option to the very_good test command that
allows users to choose between:
- imports (default): collect coverage from imported files only (current behavior)
- all: collect coverage from all Dart files in the project, showing 0% for untested files

This enables stricter coverage requirements that account for all project files,
not just those exercised by tests. Works with both Flutter and Dart projects.

Implementation details:
- Added CoverageCollectionMode enum with imports/all modes
- Implemented _discoverDartFilesForCoverage() to find all .dart files
- Implemented _enhanceLcovWithUntestedFiles() to add untested files to LCOV
- Updated command-line parsing in test.dart and dart_test_command.dart
- Threaded the option through the entire call chain
- Respects existing --exclude-coverage and --report-on options

Usage examples:
  very_good test --coverage
  very_good test --coverage --collect-coverage-from all
  very_good test --min-coverage 100 --collect-coverage-from all
  very_good test --coverage --collect-coverage-from all --exclude-coverage '**/*.g.dart'

Files modified:
- lib/src/cli/test_cli_runner.dart: Core implementation with enum, helpers, and logic
- lib/src/commands/test/test.dart: Added option to Flutter test command
- lib/src/commands/dart/commands/dart_test_command.dart: Added option to Dart test command
- lib/src/cli/flutter_cli.dart: Thread parameter through Flutter CLI
- lib/src/cli/dart_cli.dart: Thread parameter through Dart CLI
- test/src/commands/test/test_test.dart: Updated Flutter test command tests
- test/src/commands/dart/commands/dart_test_test.dart: Updated Dart test command tests with correct help text alignment

Author: meylis1998

lib/src/cli/test_cli_runner.dart

@@ -25,7 +25,8 @@ enum CoverageCollectionMode {
   imports,
 
   /// Collect coverage from all files in the project.
-  all;
+  all
+  ;
 
   /// Parses a string value into a [CoverageCollectionMode].
   static CoverageCollectionMode fromString(String value) {

lib/src/commands/dart/commands/dart_test_command.dart

@@ -39,8 +39,9 @@ class DartTestOptions {
     final excludeFromCoverage = argResults['exclude-coverage'] as String?;
     final collectCoverageFromString =
         argResults['collect-coverage-from'] as String? ?? 'imports';
-    final collectCoverageFrom =
-        CoverageCollectionMode.fromString(collectCoverageFromString);
+    final collectCoverageFrom = CoverageCollectionMode.fromString(
+      collectCoverageFromString,
+    );
     final randomOrderingSeed =
         argResults['test-randomize-ordering-seed'] as String?;
     final randomSeed = randomOrderingSeed == 'random'
@@ -200,7 +201,8 @@ class DartTestCommand extends Command<int> {
       )
       ..addOption(
         'collect-coverage-from',
-        help: 'Whether to collect coverage from imported files only or all '
+        help:
+            'Whether to collect coverage from imported files only or all '
             'files.',
         allowed: ['imports', 'all'],
         defaultsTo: 'imports',

lib/src/commands/test/test.dart

@@ -41,8 +41,9 @@ class FlutterTestOptions {
     final excludeFromCoverage = argResults['exclude-coverage'] as String?;
     final collectCoverageFromString =
         argResults['collect-coverage-from'] as String? ?? 'imports';
-    final collectCoverageFrom =
-        CoverageCollectionMode.fromString(collectCoverageFromString);
+    final collectCoverageFrom = CoverageCollectionMode.fromString(
+      collectCoverageFromString,
+    );
     final randomOrderingSeed =
         argResults['test-randomize-ordering-seed'] as String?;
     final randomSeed = randomOrderingSeed == 'random'
@@ -214,7 +215,8 @@ class TestCommand extends Command<int> {
       )
       ..addOption(
         'collect-coverage-from',
-        help: 'Whether to collect coverage from imported files only or all '
+        help:
+            'Whether to collect coverage from imported files only or all '
             'files.',
         allowed: ['imports', 'all'],
         defaultsTo: 'imports',

test/src/commands/dart/commands/dart_test_test.dart

@@ -24,26 +24,26 @@ const expectedTestUsage = [
   'Run tests in a Dart project.\n'
       '\n'
       'Usage: very_good dart test [arguments]\n'
-      '-h, --help                            Print this usage information.\n'
-      '    --coverage                        Whether to collect coverage information.\n'
-      '-r, --recursive                       Run tests recursively for all nested packages.\n'
-      '    --[no-]optimization               Whether to apply optimizations for test performance.\n'
-      '                                      Automatically disabled when --platform is specified.\n'
-      '                                      Add the `skip_very_good_optimization` tag to specific test files to disable them individually.\n'
-      '                                      (defaults to on)\n'
-      '-j, --concurrency                     The number of concurrent test suites run. Automatically set to 1 when --platform is specified.\n'
-      '                                      (defaults to "4")\n'
-      '-t, --tags                            Run only tests associated with the specified tags.\n'
-      "    --exclude-coverage                A glob which will be used to exclude files that match from the coverage (e.g. '**/*.g.dart').\n"
-      '-x, --exclude-tags                    Run only tests that do not have the specified tags.\n'
+      '-h, --help                                   Print this usage information.\n'
+      '    --coverage                               Whether to collect coverage information.\n'
+      '-r, --recursive                              Run tests recursively for all nested packages.\n'
+      '    --[no-]optimization                      Whether to apply optimizations for test performance.\n'
+      '                                             Automatically disabled when --platform is specified.\n'
+      '                                             Add the `skip_very_good_optimization` tag to specific test files to disable them individually.\n'
+      '                                             (defaults to on)\n'
+      '-j, --concurrency                            The number of concurrent test suites run. Automatically set to 1 when --platform is specified.\n'
+      '                                             (defaults to "4")\n'
+      '-t, --tags                                   Run only tests associated with the specified tags.\n'
+      "    --exclude-coverage                       A glob which will be used to exclude files that match from the coverage (e.g. '**/*.g.dart').\n"
+      '-x, --exclude-tags                           Run only tests that do not have the specified tags.\n'
       '    --min-coverage                           Whether to enforce a minimum coverage percentage.\n'
       '    --collect-coverage-from=<imports|all>    Whether to collect coverage from imported files only or all files.\n'
       '                                             [imports (default), all]\n'
-      '    --test-randomize-ordering-seed    The seed to randomize the execution order of test cases within test files.\n'
-      '    --fail-fast                       Stop running tests after the first failure.\n'
-      '    --force-ansi                      Whether to force ansi output. If not specified, it will maintain the default behavior based on stdout and stderr.\n'
-      '    --report-on=<lib/>                An optional file path to report coverage information to. This should be a path relative to the current working directory.\n'
-      '    --platform=<chrome|vm>            The platform to run tests on. \n'
+      '    --test-randomize-ordering-seed           The seed to randomize the execution order of test cases within test files.\n'
+      '    --fail-fast                              Stop running tests after the first failure.\n'
+      '    --force-ansi                             Whether to force ansi output. If not specified, it will maintain the default behavior based on stdout and stderr.\n'
+      '    --report-on=<lib/>                       An optional file path to report coverage information to. This should be a path relative to the current working directory.\n'
+      '    --platform=<chrome|vm>                   The platform to run tests on. \n'
       '\n'
       'Run "very_good help" to see global options.',
 ];
@@ -120,8 +120,9 @@ void main() {
       when<dynamic>(() => argResults['fail-fast']).thenReturn(false);
       when<dynamic>(() => argResults['optimization']).thenReturn(true);
       when<dynamic>(() => argResults['platform']).thenReturn(null);
-      when<dynamic>(() => argResults['collect-coverage-from'])
-          .thenReturn('imports');
+      when<dynamic>(
+        () => argResults['collect-coverage-from'],
+      ).thenReturn('imports');
       when<dynamic>(() => argResults['report-on']).thenReturn(null);
       when(() => argResults.rest).thenReturn([]);
     });

test/src/commands/test/test_test.dart

@@ -122,8 +122,9 @@ void main() {
       when<dynamic>(() => argResults['fail-fast']).thenReturn(false);
       when<dynamic>(() => argResults['optimization']).thenReturn(true);
       when<dynamic>(() => argResults['platform']).thenReturn(null);
-      when<dynamic>(() => argResults['collect-coverage-from'])
-          .thenReturn('imports');
+      when<dynamic>(
+        () => argResults['collect-coverage-from'],
+      ).thenReturn('imports');
       when(() => argResults.rest).thenReturn([]);
     });