feat: migrate to null-safety (#24)

2025-07-04 13:27:55 +08:00 · 2021-03-04 11:56:17 +08:00
parent 71b7e45d8e
commit 5edfa2e981
24 changed files with 758 additions and 177 deletions
--- a/.gitignore
+++ b/.gitignore
@ -8,6 +8,7 @@
 .buildlog/
 .history
 .svn/
+#*.env

 # IntelliJ related
 *.iml
@ -34,4 +35,3 @@ build/
 !example/ios/**/default.pbxuser
 !example/ios/**/default.perspectivev3
 !/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages
-.env*
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -9,6 +9,19 @@ Release notes are available on [github][notes].
 [pub-semver-readme]: https://pub.dartlang.org/packages/pub_semver
 [notes]: https://github.com/java-james/flutter_dotenv/releases

+4.0.0-nullsafety.0
+-----
+
+- [BREAKING] Opt into null-safety
+- [deps] Upgrade dart sdk constraints to ```>=2.12.0-0 <3.0.0```
+- [new] Allow for escape of $ ' " and \n characters
+- [fix] Ensure swallow function only removes leading 'export' keyword
+- [fix] Retain spaces within single or double quotes
+- [fix] Allow for comments after matching end quotes
+- [new] Migrate to null safety
+- [new] Create unit test cases for parse
+
+
 #### 3.1.0

 - [new] Allow merging with a custom map on load
--- a/README.md
+++ b/README.md
@ -52,7 +52,7 @@ Add the `.env` file to your assets bundle in `pubspec.yaml`
 Optionally add the `.env` file as an entry in your `.gitignore` if it isn't already

 ```sh
-.env*
+*.env
 ```

 Load the `.env` file in `main.dart`
--- a/example/.gitignore
+++ b/example/.gitignore
@ -250,3 +250,4 @@ GoogleService-Info.plist
 google-services.json
 # Plugins (already resolved through pubspec.yaml)
 .flutter-plugins
+*.env
--- a/example/.metadata
+++ b/example/.metadata
@ -0,0 +1,10 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 4b50ca7f7fbf56be72e54cd200825b760416a356
+  channel: beta
+
+project_type: app
--- a/example/android/app/src/main/kotlin/com/example/example/MainActivity.kt
+++ b/example/android/app/src/main/kotlin/com/example/example/MainActivity.kt
@ -0,0 +1,6 @@
+package com.example.example
+
+import io.flutter.embedding.android.FlutterActivity
+
+class MainActivity: FlutterActivity() {
+}
--- a/example/android/app/src/main/res/drawable-v21/launch_background.xml
+++ b/example/android/app/src/main/res/drawable-v21/launch_background.xml
@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="?android:colorBackground" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
+</layer-list>
--- a/example/android/app/src/main/res/values-night/styles.xml
+++ b/example/android/app/src/main/res/values-night/styles.xml
@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is on -->
+    <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <!-- Show a splash screen on the activity. Automatically removed when
+             Flutter draws its first frame -->
+        <item name="android:windowBackground">@drawable/launch_background</item>
+    </style>
+    <!-- Theme applied to the Android Window as soon as the process has started.
+         This theme determines the color of the Android Window while your
+         Flutter UI initializes, as well as behind your Flutter UI while its
+         running.
+         
+         This Theme is only used starting with V2 of Flutter's Android embedding. -->
+    <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <item name="android:windowBackground">?android:colorBackground</item>
+    </style>
+</resources>
--- a/example/assets/.env
+++ b/example/assets/.env
@ -0,0 +1,31 @@
+FOO=foo
+BAR=bar
+FOOBAR=\$FOO$BAR
+ESCAPED_DOLLAR_SIGN="\$1000"
+ESCAPED_QUOTE='\''
+
+BASIC=basic
+
+BASIC=basic1
+
+# previous line intentionally left blank
+AFTER_LINE=after_line
+EMPTY=
+SINGLE_QUOTES='single_quotes'
+SINGLE_QUOTES_SPACED='    single quotes    '
+DOUBLE_QUOTES="double_quotes"
+DOUBLE_QUOTES_SPACED="    double quotes    "
+ EXPAND_NEWLINES="expand\nnew\nlines"
+ DONT_EXPAND_UNQUOTED=dontexpand\nnewlines
+ DONT_EXPAND_SQUOTED='dontexpand\nnewlines'
+# COMMENTS=work
+EQUAL_SIGNS=equals==
+RETAIN_INNER_QUOTES={"foo": "bar"}
+RETAIN_LEADING_DQUOTE="retained
+RETAIN_LEADING_SQUOTE='retained
+RETAIN_TRAILING_DQUOTE=retained"
+RETAIN_TRAILING_SQUOTE=retained'
+RETAIN_INNER_QUOTES_AS_STRING='{"foo": "bar"}'
+TRIM_SPACE_FROM_UNQUOTED=    some spaced out string
+USERNAME=therealnerdybeast@example.tld
+    SPACED_KEY = parsed
--- a/example/lib/main.dart
+++ b/example/lib/main.dart
@ -1,70 +1,43 @@
-import 'dart:io';
-
 import 'package:flutter/material.dart';
-import 'package:flutter_dotenv/flutter_dotenv.dart' as DotEnv;
+import 'package:flutter/services.dart';
+import 'package:flutter_dotenv/flutter_dotenv.dart' as dotenv;

 Future main() async {
-  await DotEnv.load();
+  await dotenv.load(mergeWith: {
+    'TEST_VAR': '5',
+  }); // mergeWith optional, you can include Platform.environment for Mobile/Desktop app
+
  runApp(MyApp());
 }

 class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) => MaterialApp(
-        title: 'Flutter Demo',
-        theme: ThemeData(
-          primarySwatch: Colors.blue,
-          visualDensity: VisualDensity.adaptivePlatformDensity,
-        ),
-        home: MyHomePage(title: 'Flutter Demo Home Page'),
-      );
-}
-
-class MyHomePage extends StatefulWidget {
-  MyHomePage({Key key, this.title}) : super(key: key);
-
-  final String title;
-
-  @override
-  _MyHomePageState createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
-
-  void _incrementCounter() {
-    print(DotEnv.env);
-    setState(() {
-      _counter++;
-    });
-  }
-
-  @override
-  Widget build(BuildContext context) => Scaffold(
-        appBar: AppBar(
-          title: Text(widget.title),
-        ),
-        body: Center(
-          child: Column(
-            mainAxisAlignment: MainAxisAlignment.center,
-            children: <Widget>[
-              Text(
-                'You have pushed the button this many times:}',
+        title: 'Dotenv Demo',
+        home: Scaffold(
+          appBar: AppBar(
+            title: Text('Dotenv Demo'),
+          ),
+          body: SingleChildScrollView(
+            child: FutureBuilder<String>(
+              future: rootBundle.loadString('assets/.env'),
+              initialData: '',
+              builder: (context, snapshot) => Container(
+                padding: EdgeInsets.all(50),
+                child: Column(
+                  children: [
+                    Text(
+                      'Env map: ${dotenv.env.toString()}',
+                    ),
+                    Divider(thickness: 5),
+                    Text('Original'),
+                    Divider(),
+                    Text(snapshot.data ?? ''),
+                  ],
+                ),
              ),
-              Text(
-                '$_counter',
-                style: Theme.of(context).textTheme.headline4,
-              ),
-              Text(
-                'Env map: ${DotEnv.env}',
-              ),
-            ],
+            ),
          ),
        ),
-        floatingActionButton: FloatingActionButton(
-          onPressed: _incrementCounter,
-          tooltip: 'Increment',
-          child: Icon(Icons.add),
-        ), // This trailing comma makes auto-formatting nicer for build methods.
      );
 }
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@ -18,7 +18,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1

 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: ">=2.12.0-0 <3.0.0"

 dependencies:
  flutter:
@ -40,37 +40,5 @@ dev_dependencies:

 # The following section is specific to Flutter.
 flutter:
-
-  # The following line ensures that the Material Icons font is
-  # included with your application, so that you can use the icons in
-  # the material Icons class.
-  uses-material-design: true
-
  assets:
-    - .env
-
-  # An image asset can refer to one or more resolution-specific "variants", see
-  # https://flutter.dev/assets-and-images/#resolution-aware.
-
-  # For details regarding adding assets from package dependencies, see
-  # https://flutter.dev/assets-and-images/#from-packages
-
-  # To add custom fonts to your application, add a fonts section here,
-  # in this "flutter" section. Each entry in this list should have a
-  # "family" key with the font family name, and a "fonts" key with a
-  # list giving the asset and other descriptors for the font. For
-  # example:
-  # fonts:
-  #   - family: Schyler
-  #     fonts:
-  #       - asset: fonts/Schyler-Regular.ttf
-  #       - asset: fonts/Schyler-Italic.ttf
-  #         style: italic
-  #   - family: Trajan Pro
-  #     fonts:
-  #       - asset: fonts/TrajanPro.ttf
-  #       - asset: fonts/TrajanPro_Bold.ttf
-  #         weight: 700
-  #
-  # For details regarding fonts from package dependencies,
-  # see https://flutter.dev/custom-fonts/#from-packages
+    - assets/.env
--- a/example/test/widget_test.dart
+++ b/example/test/widget_test.dart
@ -1,30 +1 @@
-// This is a basic Flutter widget test.
-//
-// To perform an interaction with a widget in your test, use the WidgetTester
-// utility that Flutter provides. For example, you can send tap and scroll
-// gestures. You can also use WidgetTester to find child widgets in the widget
-// tree, read text, and verify that the values of widget properties are correct.
-
-import 'package:flutter/material.dart';
-import 'package:flutter_test/flutter_test.dart';
-
-import 'package:flutter_dotenv_example/main.dart';
-
-void main() {
-  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
-    // Build our app and trigger a frame.
-    await tester.pumpWidget(MyApp());
-
-    // Verify that our counter starts at 0.
-    expect(find.text('0'), findsOneWidget);
-    expect(find.text('1'), findsNothing);
-
-    // Tap the '+' icon and trigger a frame.
-    await tester.tap(find.byIcon(Icons.add));
-    await tester.pump();
-
-    // Verify that our counter has incremented.
-    expect(find.text('0'), findsNothing);
-    expect(find.text('1'), findsOneWidget);
-  });
-}
+void main() {}
--- a/example/web/favicon.png
+++ b/example/web/favicon.png
--- a/example/web/icons/Icon-192.png
+++ b/example/web/icons/Icon-192.png
--- a/example/web/icons/Icon-512.png
+++ b/example/web/icons/Icon-512.png
--- a/example/web/index.html
+++ b/example/web/index.html
@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <!--
+    If you are serving your web app in a path other than the root, change the
+    href value below to reflect the base path you are serving from.
+
+    The path provided below has to start and end with a slash "/" in order for
+    it to work correctly.
+
+    Fore more details:
+    * https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
+  -->
+  <base href="/">
+
+  <meta charset="UTF-8">
+  <meta content="IE=Edge" http-equiv="X-UA-Compatible">
+  <meta name="description" content="A new Flutter project.">
+
+  <!-- iOS meta tags & icons -->
+  <meta name="apple-mobile-web-app-capable" content="yes">
+  <meta name="apple-mobile-web-app-status-bar-style" content="black">
+  <meta name="apple-mobile-web-app-title" content="example">
+  <link rel="apple-touch-icon" href="icons/Icon-192.png">
+
+  <!-- Favicon -->
+  <link rel="icon" type="image/png" href="favicon.png"/>
+
+  <title>example</title>
+  <link rel="manifest" href="manifest.json">
+</head>
+<body>
+  <!-- This script installs service_worker.js to provide PWA functionality to
+       application. For more information, see:
+       https://developers.google.com/web/fundamentals/primers/service-workers -->
+  <script>
+    if ('serviceWorker' in navigator) {
+      window.addEventListener('flutter-first-frame', function () {
+        navigator.serviceWorker.register('flutter_service_worker.js');
+      });
+    }
+  </script>
+  <script src="main.dart.js" type="application/javascript"></script>
+</body>
+</html>
--- a/example/web/manifest.json
+++ b/example/web/manifest.json
@ -0,0 +1,23 @@
+{
+    "name": "example",
+    "short_name": "example",
+    "start_url": ".",
+    "display": "standalone",
+    "background_color": "#0175C2",
+    "theme_color": "#0175C2",
+    "description": "A new Flutter project.",
+    "orientation": "portrait-primary",
+    "prefer_related_applications": false,
+    "icons": [
+        {
+            "src": "icons/Icon-192.png",
+            "sizes": "192x192",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-512.png",
+            "sizes": "512x512",
+            "type": "image/png"
+        }
+    ]
+}
--- a/lib/src/dotenv.dart
+++ b/lib/src/dotenv.dart
@ -58,11 +58,25 @@ Future load(
  _isInitialized = true;
 }

+Future testLoad(
+    {String fileInput = '',
+    Parser parser = const Parser(),
+    Map<String, String> mergeWith = const {}}) async {
+  clean();
+  final linesFromFile = fileInput.split('\n');
+  final linesFromMergeWith =
+      mergeWith.entries.map((entry) => "${entry.key}=${entry.value}").toList();
+  final allLines = linesFromMergeWith..addAll(linesFromFile);
+  final envEntries = parser.parse(allLines);
+  _envMap.addAll(envEntries);
+  _isInitialized = true;
+}
+
 /// True if all supplied variables have nonempty value; false otherwise.
 /// Differs from [containsKey](dart:core) by excluding null values.
 /// Note [load] should be called first.
 bool isEveryDefined(Iterable<String> vars) =>
-    vars.every((k) => _envMap[k] != null && _envMap[k].isNotEmpty);
+    vars.every((k) => _envMap[k]?.isNotEmpty ?? false);

 Future<List<String>> _getEntriesFromFile(String filename) async {
  try {
--- a/lib/src/parser.dart
+++ b/lib/src/parser.dart
@ -1,14 +1,13 @@
-import 'package:meta/meta.dart';
-
 /// Creates key-value pairs from strings formatted as environment
 /// variable definitions.
 class Parser {
  static const _singleQuot = "'";
-  static const _keyword = 'export';
-
-  static final _comment = RegExp(r'''#.*(?:[^'"])$''');
-  static final _surroundQuotes = RegExp(r'''^(['"])(.*)\1$''');
-  static final _bashVar = RegExp(r'(?:\\)?(\$)(?:{)?([a-zA-Z_][\w]*)+(?:})?');
+  static final _leadingExport = RegExp(r'''^ *export ?''');
+  static final _comment = RegExp(r'''#[^'"]*$''');
+  static final _commentWithQuotes = RegExp(r'''#.*$''');
+  static final _surroundQuotes = RegExp(r'''^(["'])(.*?[^\\])\1''');
+  static final _bashVar =
+      RegExp(r'(?<=^|[^\\])(\$)(?:{)?([a-zA-Z_][\w]*)+(?:})?');

  /// [Parser] methods are pure functions.
  const Parser();
@ -17,18 +16,17 @@ class Parser {
  /// Duplicate keys are silently discarded.
  Map<String, String> parse(Iterable<String> lines) {
    var out = <String, String>{};
-    lines.forEach((line) {
+    for (var line in lines) {
      var kv = parseOne(line, env: out);
-      if (kv.isEmpty) return;
+      if (kv.isEmpty) continue;
      out.putIfAbsent(kv.keys.single, () => kv.values.single);
-    });
+    }
    return out;
  }

  /// Parses a single line into a key-value pair.
-  @visibleForTesting
  Map<String, String> parseOne(String line,
-      {Map<String, String> env: const {}}) {
+      {Map<String, String> env = const {}}) {
    var stripped = strip(line);
    if (!_isValid(stripped)) return {};

@ -40,48 +38,50 @@ class Parser {
    var rhs = stripped.substring(idx + 1, stripped.length).trim();
    var quotChar = surroundingQuote(rhs);
    var v = unquote(rhs);
-
    if (quotChar == _singleQuot) {
+      v = v.replaceAll("\\'", "'");
      return {k: v};
    }
-
-    final interpolatedValue = interpolate(v, env);
+    if (quotChar == '"') {
+      v = v.replaceAll('\\"', '"').replaceAll('\\n', '\n');
+    }
+    final interpolatedValue = interpolate(v, env).replaceAll("\\\$", "\$");
    return {k: interpolatedValue};
  }

  /// Substitutes $bash_vars in [val] with values from [env].
-  @visibleForTesting
-  String interpolate(String val, Map<String, String> env) =>
+  String interpolate(String val, Map<String, String?> env) =>
      val.replaceAllMapped(_bashVar, (m) {
-        var k = m.group(2);
+        var k = m.group(2)!;
        if (!_has(env, k)) return '';
-        return env[k];
+        return env[k]!;
      });

  /// If [val] is wrapped in single or double quotes, returns the quote character.
  /// Otherwise, returns the empty string.
-  @visibleForTesting
+
  String surroundingQuote(String val) {
    if (!_surroundQuotes.hasMatch(val)) return '';
-    return _surroundQuotes.firstMatch(val).group(1);
+    return _surroundQuotes.firstMatch(val)!.group(1)!;
  }

  /// Removes quotes (single or double) surrounding a value.
-  @visibleForTesting
-  String unquote(String val) =>
-      val.replaceFirstMapped(_surroundQuotes, (m) => m[2]).trim();
+  String unquote(String val) {
+    if (!_surroundQuotes.hasMatch(val))
+      return strip(val, includeQuotes: true).trim();
+    return _surroundQuotes.firstMatch(val)!.group(2)!;
+  }

  /// Strips comments (trailing or whole-line).
-  @visibleForTesting
-  String strip(String line) => line.replaceAll(_comment, '').trim();
+  String strip(String line, {bool includeQuotes = false}) =>
+      line.replaceAll(includeQuotes ? _commentWithQuotes : _comment, '').trim();

  /// Omits 'export' keyword.
-  @visibleForTesting
-  String swallow(String line) => line.replaceAll(_keyword, '').trim();
+  String swallow(String line) => line.replaceAll(_leadingExport, '').trim();

  bool _isValid(String s) => s.isNotEmpty && s.contains('=');

-  /// [null] is a valid value in a Dart map, but the env var representation is empty string, not the string 'null'
-  bool _has(Map<String, String> map, String key) =>
+  /// [ null ] is a valid value in a Dart map, but the env var representation is empty string, not the string 'null'
+  bool _has(Map<String, String?> map, String key) =>
      map.containsKey(key) && map[key] != null;
 }
--- a/pubspec.lock
+++ b/pubspec.lock
@ -1,55 +1,111 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  _fe_analyzer_shared:
+    dependency: transitive
+    description:
+      name: _fe_analyzer_shared
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "14.0.0"
+  analyzer:
+    dependency: transitive
+    description:
+      name: analyzer
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.41.2"
+  args:
+    dependency: transitive
+    description:
+      name: args
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.6.0"
  async:
    dependency: transitive
    description:
      name: async
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "2.5.0-nullsafety.1"
+    version: "2.5.0-nullsafety.3"
  boolean_selector:
    dependency: transitive
    description:
      name: boolean_selector
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0-nullsafety.3"
  characters:
    dependency: transitive
    description:
      name: characters
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.1.0-nullsafety.5"
  charcode:
    dependency: transitive
    description:
      name: charcode
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
+  cli_util:
+    dependency: transitive
+    description:
+      name: cli_util
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.2.0"
  clock:
    dependency: transitive
    description:
      name: clock
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0-nullsafety.3"
  collection:
    dependency: transitive
    description:
      name: collection
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.15.0-nullsafety.3"
+    version: "1.15.0-nullsafety.5"
+  convert:
+    dependency: transitive
+    description:
+      name: convert
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.1"
+  coverage:
+    dependency: transitive
+    description:
+      name: coverage
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.15.1"
+  crypto:
+    dependency: transitive
+    description:
+      name: crypto
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.5"
  fake_async:
    dependency: transitive
    description:
      name: fake_async
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
+  file:
+    dependency: transitive
+    description:
+      name: file
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "5.2.1"
  flutter:
    dependency: "direct main"
    description: flutter
@ -60,87 +116,283 @@ packages:
    description: flutter
    source: sdk
    version: "0.0.0"
+  glob:
+    dependency: transitive
+    description:
+      name: glob
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
+  http_multi_server:
+    dependency: transitive
+    description:
+      name: http_multi_server
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.2.0"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "3.1.4"
+  intl:
+    dependency: transitive
+    description:
+      name: intl
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.16.1"
+  io:
+    dependency: transitive
+    description:
+      name: io
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.3.4"
+  js:
+    dependency: transitive
+    description:
+      name: js
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.6.3-nullsafety.3"
+  logging:
+    dependency: transitive
+    description:
+      name: logging
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.11.4"
  matcher:
    dependency: transitive
    description:
      name: matcher
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "0.12.10-nullsafety.1"
+    version: "0.12.10-nullsafety.3"
  meta:
-    dependency: "direct main"
+    dependency: transitive
    description:
      name: meta
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0-nullsafety.6"
+  mime:
+    dependency: transitive
+    description:
+      name: mime
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.9.7"
+  node_interop:
+    dependency: transitive
+    description:
+      name: node_interop
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.1"
+  node_io:
+    dependency: transitive
+    description:
+      name: node_io
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
+  node_preamble:
+    dependency: transitive
+    description:
+      name: node_preamble
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.4.13"
+  package_config:
+    dependency: transitive
+    description:
+      name: package_config
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.9.3"
  path:
    dependency: transitive
    description:
      name: path
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.8.0-nullsafety.1"
+    version: "1.8.0-nullsafety.3"
+  pedantic:
+    dependency: transitive
+    description:
+      name: pedantic
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.10.0-nullsafety.3"
+  pool:
+    dependency: transitive
+    description:
+      name: pool
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.5.0-nullsafety.3"
+  pub_semver:
+    dependency: transitive
+    description:
+      name: pub_semver
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.4.4"
+  shelf:
+    dependency: transitive
+    description:
+      name: shelf
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.7.9"
+  shelf_packages_handler:
+    dependency: transitive
+    description:
+      name: shelf_packages_handler
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.1"
+  shelf_static:
+    dependency: transitive
+    description:
+      name: shelf_static
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.2.9+2"
+  shelf_web_socket:
+    dependency: transitive
+    description:
+      name: shelf_web_socket
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.2.4"
  sky_engine:
    dependency: transitive
    description: flutter
    source: sdk
    version: "0.0.99"
+  source_map_stack_trace:
+    dependency: transitive
+    description:
+      name: source_map_stack_trace
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.0-nullsafety.4"
+  source_maps:
+    dependency: transitive
+    description:
+      name: source_maps
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.10.10-nullsafety.3"
  source_span:
    dependency: transitive
    description:
      name: source_span
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.8.0-nullsafety.2"
+    version: "1.8.0-nullsafety.4"
  stack_trace:
    dependency: transitive
    description:
      name: stack_trace
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.10.0-nullsafety.1"
+    version: "1.10.0-nullsafety.6"
  stream_channel:
    dependency: transitive
    description:
      name: stream_channel
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0-nullsafety.3"
  string_scanner:
    dependency: transitive
    description:
      name: string_scanner
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0-nullsafety.3"
  term_glyph:
    dependency: transitive
    description:
      name: term_glyph
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
+  test:
+    dependency: "direct dev"
+    description:
+      name: test
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.16.0-nullsafety.17"
  test_api:
    dependency: transitive
    description:
      name: test_api
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "0.2.19-nullsafety.2"
+    version: "0.2.19-nullsafety.6"
+  test_core:
+    dependency: transitive
+    description:
+      name: test_core
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.3.12-nullsafety.15"
  typed_data:
    dependency: transitive
    description:
      name: typed_data
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0-nullsafety.5"
  vector_math:
    dependency: transitive
    description:
      name: vector_math
      url: "https://pub.dartlang.org"
    source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0-nullsafety.5"
+  vm_service:
+    dependency: transitive
+    description:
+      name: vm_service
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "5.5.0"
+  watcher:
+    dependency: transitive
+    description:
+      name: watcher
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.9.7+15"
+  web_socket_channel:
+    dependency: transitive
+    description:
+      name: web_socket_channel
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
+  webkit_inspection_protocol:
+    dependency: transitive
+    description:
+      name: webkit_inspection_protocol
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.7.4"
+  yaml:
+    dependency: transitive
+    description:
+      name: yaml
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.2.1"
 sdks:
-  dart: ">=2.10.0-110 <2.11.0"
+  dart: ">=2.12.0-0.0 <3.0.0"
--- a/pubspec.yaml
+++ b/pubspec.yaml
@ -1,14 +1,15 @@
 name: flutter_dotenv
-version: 3.1.0
+version: 4.0.0-nullsafety.0
 description: Easily configure any flutter application with global variables using a `.env` file.
 author: java-james <james-collins@hotmail.co.nz>
 homepage: https://github.com/java-james/flutter_dotenv
 environment:
-  sdk: '>=2.0.0 <3.0.0'
+  sdk: '>=2.12.0-0 <3.0.0'
 dependencies:
  flutter:
    sdk: flutter
-  meta: ^1.1.6
+
 dev_dependencies:
+  test:
  flutter_test:
    sdk: flutter
--- a/test/.env
+++ b/test/.env
@ -0,0 +1,31 @@
+FOO=foo
+BAR=bar
+FOOBAR=\$FOO$BAR
+ESCAPED_DOLLAR_SIGN="\$1000"
+ESCAPED_QUOTE='\''
+
+BASIC=basic
+
+BASIC=basic1
+
+# previous line intentionally left blank
+AFTER_LINE=after_line
+EMPTY=
+SINGLE_QUOTES='single_quotes'
+SINGLE_QUOTES_SPACED='    single quotes    '
+DOUBLE_QUOTES="double_quotes"
+DOUBLE_QUOTES_SPACED="    double quotes    "
+ EXPAND_NEWLINES="expand\nnew\nlines"
+ DONT_EXPAND_UNQUOTED=dontexpand\nnewlines
+ DONT_EXPAND_SQUOTED='dontexpand\nnewlines'
+# COMMENTS=work
+EQUAL_SIGNS=equals==
+RETAIN_INNER_QUOTES={"foo": "bar"}
+RETAIN_LEADING_DQUOTE="retained
+RETAIN_LEADING_SQUOTE='retained
+RETAIN_TRAILING_DQUOTE=retained"
+RETAIN_TRAILING_SQUOTE=retained'
+RETAIN_INNER_QUOTES_AS_STRING='{"foo": "bar"}'
+TRIM_SPACE_FROM_UNQUOTED=    some spaced out string
+USERNAME=therealnerdybeast@example.tld
+    SPACED_KEY = parsed
--- a/test/dotenv_test.dart
+++ b/test/dotenv_test.dart
@ -0,0 +1,42 @@
+import 'dart:io';
+import 'package:flutter_dotenv/flutter_dotenv.dart' as dotenv;
+import 'package:test/test.dart';
+
+void main() {
+  group('dotenv', () {
+    setUp(() {
+      print(Directory.current.toString());
+      dotenv.testLoad(
+          fileInput: File('.env')
+              .readAsStringSync()); //, mergeWith: Platform.environment
+    });
+    test('able to load .env', () {
+      expect(dotenv.env['FOO'], 'foo');
+      expect(dotenv.env['BAR'], 'bar');
+      expect(dotenv.env['FOOBAR'], '\$FOObar');
+      expect(dotenv.env['ESCAPED_DOLLAR_SIGN'], '\$1000');
+      expect(dotenv.env['ESCAPED_QUOTE'], "'");
+      expect(dotenv.env['BASIC'], 'basic');
+      expect(dotenv.env['AFTER_LINE'], 'after_line');
+      expect(dotenv.env['EMPTY'], '');
+      expect(dotenv.env['SINGLE_QUOTES'], 'single_quotes');
+      expect(dotenv.env['SINGLE_QUOTES_SPACED'], '    single quotes    ');
+      expect(dotenv.env['DOUBLE_QUOTES'], 'double_quotes');
+      expect(dotenv.env['DOUBLE_QUOTES_SPACED'], '    double quotes    ');
+      expect(dotenv.env['EXPAND_NEWLINES'], "expand\nnew\nlines");
+      expect(dotenv.env['DONT_EXPAND_UNQUOTED'], 'dontexpand\\nnewlines');
+      expect(dotenv.env['DONT_EXPAND_SQUOTED'], 'dontexpand\\nnewlines');
+      expect(dotenv.env['COMMENTS'], null);
+      expect(dotenv.env['EQUAL_SIGNS'], 'equals==');
+      expect(dotenv.env['RETAIN_INNER_QUOTES'], '{"foo": "bar"}');
+      expect(dotenv.env['RETAIN_LEADING_DQUOTE'], "\"retained");
+      expect(dotenv.env['RETAIN_LEADING_SQUOTE'], '\'retained');
+      expect(dotenv.env['RETAIN_TRAILING_DQUOTE'], 'retained\"');
+      expect(dotenv.env['RETAIN_TRAILING_SQUOTE'], "retained\'");
+      expect(dotenv.env['RETAIN_INNER_QUOTES_AS_STRING'], '{"foo": "bar"}');
+      expect(dotenv.env['TRIM_SPACE_FROM_UNQUOTED'], 'some spaced out string');
+      expect(dotenv.env['USERNAME'], 'therealnerdybeast@example.tld');
+      expect(dotenv.env['SPACED_KEY'], 'parsed');
+    });
+  });
+}
--- a/test/parser_test.dart
+++ b/test/parser_test.dart
@ -0,0 +1,170 @@
+import 'dart:math';
+
+import 'package:flutter_dotenv/src/parser.dart';
+import 'package:test/test.dart';
+
+const ceil = 100000;
+
+void main() {
+  late Random rand;
+  const _psr = Parser();
+  group('[Parser]', () {
+    setUp(() => rand = Random());
+    test('it swallows leading "export"', () {
+      var out = _psr.swallow(' export foo = bar  ');
+      expect(out, equals('foo = bar'));
+
+      out = _psr.swallow(' foo = bar export');
+      expect(out, equals('foo = bar export'));
+    });
+
+    test('it strips trailing comments', () {
+      var out = _psr.strip(
+          'needs="explanation"  # It was the year when they finally immanentized the Eschaton.');
+      expect(out, equals('needs="explanation"'));
+      out = _psr.strip(
+          'needs="explanation  # It was the year when they finally immanentized the Eschaton." ');
+      expect(
+          out,
+          equals(
+              'needs="explanation  # It was the year when they finally immanentized the Eschaton."'));
+      out = _psr.strip(
+          'needs=explanation  # It was the year when they finally immanentized the Eschaton."',
+          includeQuotes: true);
+      expect(out, equals('needs=explanation'));
+      out = _psr.strip('  # It was the best of times, it was a waste of time.');
+      expect(out, isEmpty);
+    });
+    test('it knows quoted # is not a comment', () {
+      var doub = _psr.parseOne('foo = "ab#c"');
+      var single = _psr.parseOne("foo = 'ab#c'");
+
+      expect(doub['foo'], equals('ab#c'));
+      expect(single['foo'], equals('ab#c'));
+    });
+    test('it handles quotes in a comment', () {
+      // note terminal whitespace
+      var sing = _psr.parseOne("fruit = 'banana' # comments can be 'sneaky!' ");
+      var doub =
+          _psr.parseOne('fruit = " banana" # comments can be "sneaky!" ');
+      var none =
+          _psr.parseOne('fruit =    banana  # comments can be "sneaky!" ');
+
+      expect(sing['fruit'], equals('banana'));
+      expect(doub['fruit'], equals(' banana'));
+      expect(none['fruit'], equals('banana'));
+    });
+    test('treats all # in unquoted as comments', () {
+      var fail =
+          _psr.parseOne('fruit = banana # I\'m a comment with a final "quote"');
+      expect(fail['fruit'], equals('banana'));
+    });
+
+    test('it handles unquoted values', () {
+      var out = _psr.unquote('   str   ');
+      expect(out, equals('str'));
+    });
+    test('it handles double quoted values', () {
+      var out = _psr.unquote('"val "');
+      expect(out, equals('val '));
+    });
+    test('it handles single quoted values', () {
+      var out = _psr.unquote("'  val'");
+      expect(out, equals('  val'));
+    });
+    test('retain trailing single quote', () {
+      var out = _psr.unquote("retained'");
+      expect(out, equals("retained'"));
+    });
+
+    // test('it handles escaped quotes within values', () { // Does not
+    //   var out = _psr.unquote('''\'val_with_\\"escaped\\"_\\'quote\\'s \'''');
+    //   expect(out, equals('''val_with_"escaped"_'quote's '''));
+    //   out = _psr.unquote("  val_with_\"escaped\"_\'quote\'s ");
+    //   expect(out, equals('''val_with_"escaped"_'quote's'''));
+    // });
+
+    test('it skips empty lines', () {
+      var out = _psr.parse([
+        '# Define environment variables.',
+        '  # comments will be stripped',
+        'foo=bar  # trailing junk',
+        ' baz =    qux',
+        '# another comment'
+      ]);
+      expect(out, equals({'foo': 'bar', 'baz': 'qux'}));
+    });
+
+    test('it ignores duplicate keys', () {
+      var out = _psr.parse(['foo=bar', 'foo=baz']);
+      expect(out, equals({'foo': 'bar'}));
+    });
+    test('it substitutes known variables into other values', () {
+      var out = _psr.parse(['foo=bar', r'baz=super$foo']);
+      expect(out, equals({'foo': 'bar', 'baz': 'superbar'}));
+    });
+    test('it discards surrounding quotes', () {
+      var out = _psr.parse([r"foo = 'bar'", r'export baz="qux"']);
+      expect(out, equals({'foo': 'bar', 'baz': 'qux'}));
+    });
+
+    test('it detects unquoted values', () {
+      var out = _psr.surroundingQuote('no quotes here!');
+      expect(out, isEmpty);
+    });
+    test('it detects double-quoted values', () {
+      var out = _psr.surroundingQuote('"double quoted"');
+      expect(out, equals('"'));
+    });
+    test('it detects single-quoted values', () {
+      var out = _psr.surroundingQuote("'single quoted'");
+      expect(out, equals("'"));
+    });
+
+    test('it performs variable substitution', () {
+      var out = _psr.interpolate(r'a$foo$baz', {'foo': 'bar', 'baz': 'qux'});
+      expect(out, equals('abarqux'));
+    });
+    test('it skips undefined variables', () {
+      var r = rand.nextInt(ceil); // avoid runtime collision with real env vars
+      var out = _psr.interpolate('a\$jinx_$r', {});
+      expect(out, equals('a'));
+    });
+    test('it handles explicitly null values in env', () {
+      var r = rand.nextInt(ceil); // avoid runtime collision with real env vars
+      var out = _psr.interpolate('a\$foo_$r\$baz_$r', {'foo_$r': null});
+      expect(out, equals('a'));
+    });
+    test('it handles \${surrounding braces} on vars', () {
+      var r = rand.nextInt(ceil); // avoid runtime collision with real env vars
+      var out = _psr.interpolate('optional_\${foo_$r}', {'foo_$r': 'curlies'});
+      expect(out, equals('optional_curlies'));
+    });
+
+    test('it handles equal signs in values', () {
+      var none = _psr.parseOne('foo=bar=qux');
+      var sing = _psr.parseOne("foo='bar=qux'");
+      var doub = _psr.parseOne('foo="bar=qux"');
+
+      expect(none['foo'], equals('bar=qux'));
+      expect(sing['foo'], equals('bar=qux'));
+      expect(doub['foo'], equals('bar=qux'));
+    });
+
+    test('it skips var substitution in single quotes', () {
+      var r = rand.nextInt(ceil); // avoid runtime collision with real env vars
+      var out = _psr.parseOne("some_var='my\$key_$r'", env: {'key_$r': 'val'});
+      expect(out['some_var'], equals('my\$key_$r'));
+    });
+    test('it performs var subs in double quotes', () {
+      var r = rand.nextInt(ceil); // avoid runtime collision with real env vars
+      var out = _psr.parseOne('some_var="my\$key_$r"', env: {'key_$r': 'val'});
+      expect(out['some_var'], equals('myval'));
+    });
+    test('it performs var subs without quotes', () {
+      var r = rand.nextInt(ceil); // avoid runtime collision with real env vars
+      var out = _psr.parseOne("some_var=my\$key_$r", env: {'key_$r': 'val'});
+      expect(out['some_var'], equals('myval'));
+    });
+  });
+}