Get variable values as int, double and bool

lib/src/dotenv.dart

@@ -56,6 +56,55 @@ class DotEnv {
     return value;
   }
 
+  /// Load the enviroment variable value as an [int]
+  ///
+  /// If variable with [name] does not exist then [fallback] will be used.
+  /// However if also no [fallback] is supplied an error will occur.
+  ///
+  /// Furthermore an [FormatException] will be thrown if the variable with [name]
+  /// exists but can not be parsed as an [int].
+  int getInt(String name, {int? fallback}) {
+    final value = maybeGet(name);
+    assert(value != null || fallback != null, 'A non-null fallback is required for missing entries');
+    return value != null ? int.parse(value) : fallback!;
+  }
+
+  /// Load the enviroment variable value as a [double]
+  ///
+  /// If variable with [name] does not exist then [fallback] will be used.
+  /// However if also no [fallback] is supplied an error will occur.
+  ///
+  /// Furthermore an [FormatException] will be thrown if the variable with [name]
+  /// exists but can not be parsed as a [double].
+  double getDouble(String name, {double? fallback}) {
+    final value = maybeGet(name);
+    assert(value != null || fallback != null, 'A non-null fallback is required for missing entries');
+    return value != null ? double.parse(value) : fallback!;
+  }
+
+  /// Load the enviroment variable value as a [bool]
+  ///
+  /// If variable with [name] does not exist then [fallback] will be used.
+  /// However if also no [fallback] is supplied an error will occur.
+  ///
+  /// Furthermore an [FormatException] will be thrown if the variable with [name]
+  /// exists but can not be parsed as a [bool].
+  bool getBool(String name, {bool? fallback}) {
+    final value = maybeGet(name);
+    assert(value != null || fallback != null, 'A non-null fallback is required for missing entries');
+    if (value != null) {
+      if (['true', '1'].contains(value.toLowerCase())) {
+        return true;
+      } else if (['false', '0'].contains(value.toLowerCase())) {
+        return false;
+      } else {
+        throw FormatException('Could not parse as a bool');
+      }
+    }
+
+    return fallback!;
+  }
+
   String? maybeGet(String name, {String? fallback}) => env[name] ?? fallback;
 
   /// Loads environment variables from the env file into a map

test/.env

@@ -4,6 +4,19 @@ FOOBAR=\$FOO${FOO}$BAR
 ESCAPED_DOLLAR_SIGN="\$1000"
 ESCAPED_QUOTE='\''
 
+BOOL_TRUE=true
+BOOL_1=1
+BOOL_FALSE=false
+BOOL_0=0
+
+INT_42=42
+INT_42_NEGATIVE=-42
+
+DOUBLE_13_37=13.37
+DOUBLE_13_37_NEGATIVE=-13.37
+DOUBLE_1e3=1.e3
+DOUBLE_POINT_3=.3
+
 BASIC=basic
 
 BASIC=basic1

test/dotenv_test.dart

@@ -14,6 +14,16 @@ void main() {
       expect(dotenv.env['FOOBAR'], '\$FOOfoobar');
       expect(dotenv.env['ESCAPED_DOLLAR_SIGN'], '\$1000');
       expect(dotenv.env['ESCAPED_QUOTE'], "'");
+      expect(dotenv.env['BOOL_TRUE'], "true");
+      expect(dotenv.env['BOOL_1'], "1");
+      expect(dotenv.env['BOOL_FALSE'], "false");
+      expect(dotenv.env['BOOL_0'], "0");
+      expect(dotenv.env['INT_42'], "42");
+      expect(dotenv.env['INT_42_NEGATIVE'], "-42");
+      expect(dotenv.env['DOUBLE_13_37'], "13.37");
+      expect(dotenv.env['DOUBLE_13_37_NEGATIVE'], "-13.37");
+      expect(dotenv.env['DOUBLE_1e3'], "1.e3");
+      expect(dotenv.env['DOUBLE_POINT_3'], ".3");
       expect(dotenv.env['BASIC'], 'basic');
       expect(dotenv.env['AFTER_LINE'], 'after_line');
       expect(dotenv.env['EMPTY'], '');
@@ -46,5 +56,31 @@ void main() {
       expect(dotenv.maybeGet('COMMENTS'), null);
       expect(dotenv.maybeGet('EQUAL_SIGNS', fallback: 'sample'), 'equals==');
     });
+    test('int getting works', () {
+      expect(dotenv.getInt('INT_42'), 42);
+      expect(dotenv.getInt('INT_42_NEGATIVE'), -42);
+      expect(() => dotenv.getInt('COMMENTS'), throwsAssertionError);
+      expect(dotenv.getInt('COMMENTS', fallback: 42), 42);
+      expect(() => dotenv.getInt('FOO'), throwsFormatException);
+    });
+    test('double getting works', () {
+      expect(dotenv.getDouble('DOUBLE_13_37'), 13.37);
+      expect(dotenv.getDouble('DOUBLE_13_37_NEGATIVE'), -13.37);
+      expect(dotenv.getDouble('DOUBLE_1e3'), 1e3);
+      expect(dotenv.getDouble('DOUBLE_POINT_3'), .3);
+      expect(() => dotenv.getDouble('COMMENTS'), throwsAssertionError);
+      expect(dotenv.getDouble('COMMENTS', fallback: .3), .3);
+      expect(() => dotenv.getDouble('FOO'), throwsFormatException);
+    });
+    test('bool getting works', () {
+      expect(dotenv.getBool('BOOL_TRUE'), true);
+      expect(dotenv.getBool('BOOL_1'), true);
+      expect(dotenv.getBool('BOOL_FALSE'), false);
+      expect(dotenv.getBool('BOOL_0'), false);
+      expect(() => dotenv.getBool('COMMENTS'), throwsAssertionError);
+      expect(dotenv.getBool('COMMENTS', fallback: true), true);
+      expect(dotenv.getBool('COMMENTS', fallback: false), false);
+      expect(() => dotenv.getBool('FOO'), throwsFormatException);
+    });
   });
 }