update dart to 3.9.2

.fvmrc

@@ -0,0 +1,3 @@
+{
+  "flutter": "stable"
+}

.github/workflows/dart.yml

@@ -10,7 +10,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     container:
-      image:  google/dart:2.12.0-133.2.beta
+      image: dart:stable
 
     steps:
       - uses: actions/checkout@v2
@@ -29,7 +29,14 @@ jobs:
       # package:test for this step to succeed. Note that Flutter projects will
       # want to change this to 'flutter test'.
       - name: Run tests
-        run: dart run test_coverage #test --coverage=coverage
+        run: dart test --coverage=coverage
+
+      - name: Install coverage tool
+        run: dart pub global activate coverage
+
+      - name: Convert coverage to lcov
+        run: dart pub global run coverage:format_coverage --lcov -i coverage -o coverage/lcov.info --report-on=lib
+
       - uses: codecov/codecov-action@v1.0.2
         with:
           token: ${{secrets.CODECOV_TOKEN}} #required

.gitignore

@@ -75,3 +75,6 @@ build/
 !**/ios/**/default.mode2v3
 !**/ios/**/default.pbxuser
 !**/ios/**/default.perspectivev3
+
+# FVM Version Cache
+.fvm/

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+  "dart.flutterSdkPath": ".fvm/versions/stable"
+}

CLAUDE.md

@@ -0,0 +1,61 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+Stringr is a comprehensive string manipulation library for Dart/Flutter inspired by VocaJS. It provides powerful string operations that work with Latin, non-Latin, and grapheme cluster strings using complex regular expressions rather than simple whitespace splitting.
+
+**Current Status**: Updated to Dart 3.0+ with modern SDK constraints and comprehensive linting rules.
+
+## Development Commands
+
+### Testing
+- `dart test` - Run all tests
+- `dart run test_coverage` - Run tests with coverage (used in CI)
+- `dart test test/specific_test.dart` - Run specific test file
+
+### Dependencies
+- `dart pub get` - Install dependencies
+- `dart pub upgrade` - Upgrade dependencies
+
+### Analysis
+- `dart analyze` - Static analysis with comprehensive modern Dart linting rules
+
+## Architecture Overview
+
+The library follows a **modular extension-based architecture** with functionality organized into domain-specific modules:
+
+### Core Modules
+- **`lib/src/case/`** - Case transformations (camelCase, kebabCase, snakeCase, titleCase)
+- **`lib/src/chop/`** - String truncation operations (truncate, slice, prune, first, last)  
+- **`lib/src/count/`** - Counting operations (characters, graphemes, occurrences, words)
+- **`lib/src/escape/`** - String escaping/unescaping (HTML, RegExp)
+- **`lib/src/manipulate/`** - String manipulation (insert, reverse, slugify, translate, splice)
+- **`lib/src/split/`** - String splitting operations (words, chars, codePoints, graphemes)
+
+### Utility Infrastructure
+- **`lib/src/util/object/`** - Generic utility extensions (ExtendedIterable)
+- **`lib/src/util/regex/`** - Pre-compiled regex patterns and constants for Unicode handling
+- **`lib/src/util/strings/`** - String utility functions, diacritics mapping, and surrogate pair handling
+
+### Key Patterns
+- Each module implements a Dart extension on `String` class
+- Heavy use of pre-compiled regex patterns for Unicode-aware text processing
+- Consistent method signatures with optional parameters and sensible defaults
+- Support for complex Unicode scenarios including surrogate pairs and grapheme clusters
+
+## Dependencies
+- **`characters`** ^1.3.0 - Used for grapheme cluster support and Unicode handling (Flutter-compatible version)
+- **`test`** ^1.26.3 - Modern testing framework (dev dependency)
+
+## Important Notes
+- Project uses dependency overrides for `file` and `watcher` packages to ensure Dart 3.0+ compatibility
+- The codebase has comprehensive linting rules enforced through `analysis_options.yaml`
+- All tests pass on Dart 3.0+ but there are linting warnings that can be addressed incrementally
+
+## CI/CD
+- GitHub Actions workflow runs on push/PR to master branch
+- Uses latest stable Dart container (`dart:stable`)
+- Runs tests with coverage and uploads to Codecov
+- Coverage reports stored in `coverage/lcov.info`

analysis_options.yaml

@@ -1,7 +1,124 @@
 analyzer:
-  enable-experiment:
-    - non-nullable
-
+  language:
+    strict-casts: true
+    strict-inference: true
+    strict-raw-types: true
+
 linter:
   rules:
-    - public_member_api_docs
+    # Error rules
+    - always_use_package_imports
+    - avoid_dynamic_calls
+    - avoid_empty_else
+    - avoid_slow_async_io
+    - cancel_subscriptions
+    - close_sinks
+    - comment_references
+    - control_flow_in_finally
+    - empty_statements
+    - hash_and_equals
+    - no_adjacent_strings_in_list
+    - no_duplicate_case_values
+    - no_logic_in_create_state
+    - prefer_void_to_null
+    - test_types_in_equals
+    - throw_in_finally
+    - unrelated_type_equality_checks
+    - use_build_context_synchronously
+    - use_key_in_widget_constructors
+    - valid_regexps
+
+    # Style rules
+    - always_declare_return_types
+    - always_put_control_body_on_new_line
+    - always_put_required_named_parameters_first
+    - annotate_overrides
+    - avoid_bool_literals_in_conditional_expressions
+    - avoid_catches_without_on_clauses
+    - avoid_catching_errors
+    - avoid_field_initializers_in_const_classes
+    - avoid_function_literals_in_foreach_calls
+    - avoid_init_to_null
+    - avoid_null_checks_in_equality_operators
+    - avoid_print
+    - avoid_redundant_argument_values
+    - avoid_renaming_method_parameters
+    - avoid_return_types_on_setters
+    - avoid_returning_null_for_void
+    - avoid_single_cascade_in_expression_statements
+    - avoid_types_as_parameter_names
+    - avoid_unnecessary_containers
+    - avoid_unused_constructor_parameters
+    - avoid_void_async
+    - camel_case_extensions
+    - camel_case_types
+    - cascade_invocations
+    - constant_identifier_names
+    - curly_braces_in_flow_control_structures
+    - directives_ordering
+    - empty_catches
+    - empty_constructor_bodies
+    - file_names
+    - library_names
+    - library_prefixes
+    - non_constant_identifier_names
+    - null_closures
+    - omit_local_variable_types
+    - one_member_abstracts
+    - only_throw_errors
+    - overridden_fields
+    - package_names
+    - prefer_adjacent_string_concatenation
+    - prefer_collection_literals
+    - prefer_conditional_assignment
+    - prefer_const_constructors
+    - prefer_const_constructors_in_immutables
+    - prefer_const_declarations
+    - prefer_const_literals_to_create_immutables
+    - prefer_constructors_over_static_methods
+    - prefer_contains
+    - prefer_final_fields
+    - prefer_final_in_for_each
+    - prefer_final_locals
+    - prefer_for_elements_to_map_fromIterable
+    - prefer_function_declarations_over_variables
+    - prefer_generic_function_type_aliases
+    - prefer_if_elements_to_conditional_expressions
+    - prefer_if_null_operators
+    - prefer_initializing_formals
+    - prefer_inlined_adds
+    - prefer_interpolation_to_compose_strings
+    - prefer_is_empty
+    - prefer_is_not_empty
+    - prefer_iterable_whereType
+    - prefer_null_aware_operators
+    - prefer_spread_collections
+    - prefer_typing_uninitialized_variables
+    - provide_deprecation_message
+    - public_member_api_docs
+    - recursive_getters
+    - slash_for_doc_comments
+    - sort_child_properties_last
+    - sort_constructors_first
+    - sort_pub_dependencies
+    - sort_unnamed_constructors_first
+    - type_annotate_public_apis
+    - unawaited_futures
+    - unnecessary_await_in_return
+    - unnecessary_brace_in_string_interps
+    - unnecessary_const
+    - unnecessary_getters_setters
+    - unnecessary_lambdas
+    - unnecessary_new
+    - unnecessary_null_aware_assignments
+    - unnecessary_null_in_if_null_operators
+    - unnecessary_overrides
+    - unnecessary_parenthesis
+    - unnecessary_statements
+    - unnecessary_string_escapes
+    - unnecessary_string_interpolations
+    - unnecessary_this
+    - use_full_hex_values_for_flutter_colors
+    - use_function_type_syntax_for_parameters
+    - use_rethrow_when_possible
+    - void_checks