Merge pull request #4 from ukitgroup/empty-string

Empty string value fix

README.md

@@ -305,6 +305,8 @@ class CatConfig {
 
 We use our own version of [class-transformer](https://github.com/typestack/class-transformer): [@ukitgroup/class-transformer](https://github.com/ukitgroup/class-transformer)
 
+If environment variable is empty or not provided, config will use default value.
+
 ## Validation
 
 ```text

e2e-test/file.e2e-spec.ts

@@ -25,7 +25,7 @@ describe('File', () => {
       FIRST__NUMBER_VAR=1.1
       FIRST__NUMBER_VAR_WITH_DEFAULT=7.7
       FIRST__BOOL_VAR=true
-      FIRST__BOOL_VAR_WITH_DEFAULT=true
+      FIRST__BOOL_VAR_WITH_DEFAULT=
       SECOND__VARIABLE=new`,
     );
 
@@ -58,7 +58,7 @@ describe('File', () => {
       numberVar: 1.1,
       numberVarWithDefault: 7.7,
       boolVar: true,
-      boolVarWithDefault: true,
+      boolVarWithDefault: false,
     });
     expect(secondConfig).toMatchObject({
       variable: 'new',

src/lib/parser.spec.ts

@@ -30,4 +30,20 @@ describe('ConfigParser', () => {
       },
     });
   });
+
+  it('should return empty string value as undefined', () => {
+    const moduleName = 'SOME_MODULE';
+    const variableName = 'SOME_VARIABLE';
+    const value = '';
+
+    expect(
+      configParser.parse({
+        [`${moduleName}${ENV_MODULE_SEPARATOR}${variableName}`]: value,
+      }),
+    ).toMatchObject({
+      [moduleName]: {
+        [variableName]: undefined,
+      },
+    });
+  });
 });

src/lib/parser.ts

@@ -13,7 +13,8 @@ export class ConfigParser {
         }
         const moduleName = split[0];
         configStorage[moduleName] = configStorage[moduleName] || {};
-        configStorage[moduleName][split[1]] = value;
+        // interpret empty string as undefined
+        configStorage[moduleName][split[1]] = value || undefined;
       },
     );
     return configStorage;