feat(casing): add variable name casing

examples/envied_example/.env

@@ -1,2 +1,3 @@
 KEY1=VALUE1
-KEY2=VALUE2
+KEY2=VALUE2
+TEST_KEY=TEST_VALUE

examples/envied_example/lib/env.dart

@@ -15,4 +15,6 @@ abstract class Env {
   static const int key4 = _Env.key4;
   @EnviedField()
   static const bool key5 = _Env.key5;
+  @EnviedField()
+  static const String testKey = _Env.testKey;
 }

examples/envied_example/lib/example.dart

@@ -6,4 +6,5 @@ void run() {
   print(Env.key3);
   print(Env.key4);
   print(Env.key5);
+  print(Env.testKey);
 }

packages/envied_generator/lib/src/generator.dart

@@ -6,6 +6,7 @@ import 'package:build/build.dart';
 import 'package:envied/envied.dart';
 import 'package:envied_generator/src/generate_line.dart';
 import 'package:envied_generator/src/generate_line_encrypted.dart';
+import 'package:envied_generator/src/helpers/string.dart';
 import 'package:envied_generator/src/load_envs.dart';
 import 'package:source_gen/source_gen.dart';
 
@@ -52,8 +53,13 @@ class EnviedGenerator extends GeneratorForAnnotation<Envied> {
         DartObject? dartObject = enviedFieldChecker.firstAnnotationOf(fieldEl);
         ConstantReader reader = ConstantReader(dartObject);
 
-        String varName =
-            reader.read('varName').literalValue as String? ?? fieldEl.name;
+        late String varName;
+
+        if (reader.read('varName').literalValue == null) {
+          varName = normalize(fieldEl.name);
+        } else {
+          varName = reader.read('varName').literalValue as String;
+        }
 
         Object? defaultValue = reader.read('defaultValue').literalValue;
 

packages/envied_generator/lib/src/helpers/string.dart

@@ -0,0 +1,36 @@
+// Helper functions related to strings
+
+/// Method to convert camelCases to snake_cases
+String camelCaseToSnakeCase(String input) {
+  return input.replaceAllMapped(
+    RegExp('([A-Z])|([0-9]+)'),
+    (match) => '_${match.group(0)!.toLowerCase()}',
+  );
+}
+
+/// Method that will returns
+/// [a] if [a] is not null or an empty string. Otherwise,
+/// [b] will be returned.
+String ifFalsy(String? a, String b) {
+  return validate(a, (x) => (x ?? '').isNotEmpty) ? a! : b;
+}
+
+/// Method to normalize the [input] string to .ENV
+/// compatible keys.
+///
+/// For example:
+/// `isStudent1` will have an output of `IS_STUDENT_1`
+String normalize(String input) {
+  return camelCaseToSnakeCase(input).toUpperCase();
+}
+
+/// Method to decide whether a [String] input
+/// returns `true` or `false` through the predicate function
+/// or not.
+bool validate(String? input, BoolFn predicate) {
+  return predicate(input);
+}
+
+/// Type Definition: function with a [String] as a parameter
+/// returning a [bool]
+typedef BoolFn = bool Function(String?);

packages/envied_generator/test/.env.example

@@ -1,7 +1,12 @@
 test_string=test_string
 testString=testString
+TEST_STRING=TEST_STRING
 testInt=123
+TEST_INT=123
 testDouble=1.23
+TEST_DOUBLE=1.23
+TEST_BOOL=true
 testBool=true
 testDynamic=123abc
+TEST_DYNAMIC=123abc
 SYSTEM_VAR=system_var

packages/envied_generator/test/src/generator_tests.dart

@@ -25,28 +25,28 @@ abstract class Env3 {
   static const Symbol? testString = null;
 }
 
-@ShouldThrow('Type `int` do not align up to value `testString`.')
+@ShouldThrow('Type `int` do not align up to value `TEST_STRING`.')
 @Envied(path: 'test/.env.example')
 abstract class Env4 {
   @EnviedField()
   static const int? testString = null;
 }
 
-@ShouldThrow('Type `double` do not align up to value `testString`.')
+@ShouldThrow('Type `double` do not align up to value `TEST_STRING`.')
 @Envied(path: 'test/.env.example')
 abstract class Env5 {
   @EnviedField()
   static const double? testString = null;
 }
 
-@ShouldThrow('Type `num` do not align up to value `testString`.')
+@ShouldThrow('Type `num` do not align up to value `TEST_STRING`.')
 @Envied(path: 'test/.env.example')
 abstract class Env6 {
   @EnviedField()
   static const num? testString = null;
 }
 
-@ShouldThrow('Type `bool` do not align up to value `testString`.')
+@ShouldThrow('Type `bool` do not align up to value `TEST_STRING`.')
 @Envied(path: 'test/.env.example')
 abstract class Env7 {
   @EnviedField()
@@ -55,7 +55,7 @@ abstract class Env7 {
 
 @ShouldGenerate('''
 class _Env8 {
-  static const String testString = 'testString';
+  static const String testString = 'TEST_STRING';
   static const int testInt = 123;
   static const double testDouble = 1.23;
   static const bool testBool = true;
@@ -94,7 +94,7 @@ class _Env10 {
 ''')
 @Envied(path: 'test/.env.example')
 abstract class Env10 {
-  @EnviedField(varName: 'SYSTEM_VAR')
+  @EnviedField()
   static const String? systemVar = null;
 }
 
@@ -160,15 +160,15 @@ class _Env15 {
 abstract class Env15 {
   @EnviedField(defaultValue: 'test_')
   static const String? testDefaultParam = null;
-  @EnviedField()
+  @EnviedField(varName: 'testString')
   static const String testString = 'testString';
-  @EnviedField()
+  @EnviedField(varName: 'testInt')
   static const int testInt = 123;
-  @EnviedField()
+  @EnviedField(varName: 'testDouble')
   static const double testDouble = 1.23;
-  @EnviedField()
+  @EnviedField(varName: 'testBool')
   static const bool testBool = true;
-  @EnviedField()
+  @EnviedField(varName: 'testDynamic')
   static const dynamic testDynamic = '123abc';
 }