Empty string should could as null (#65)

src/config/ConfigScope.spec.ts

@@ -148,6 +148,15 @@ describe('ConfigScope', () => {
 
       expect(resolvedValue).toBeNull()
     })
+
+    it('uses default on empty string', () => {
+      process.env.value = ''
+      const configScope = new ConfigScope()
+
+      const resolvedValue = configScope.getOptionalNullable('value', 'def')
+
+      expect(resolvedValue).toBe('def')
+    })
   })
 
   describe('getOptional', () => {
@@ -397,6 +406,15 @@ describe('ConfigScope', () => {
       expect(resolvedValue).toBe('def')
     })
 
+    it('uses default value on empty string', () => {
+      process.env.value = ''
+      const configScope = new ConfigScope()
+
+      const resolvedValue = configScope.getOptionalValidated('value', 'def', validator)
+
+      expect(resolvedValue).toBe('def')
+    })
+
     it('throws an error if failing validation', () => {
       process.env.value = '12345678900'
       const configScope = new ConfigScope()
@@ -433,6 +451,19 @@ describe('ConfigScope', () => {
 
       expect(resolvedValue).toBe('def/')
     })
+
+    it('uses default value on empty string', () => {
+      process.env.value = ''
+      const configScope = new ConfigScope()
+
+      const resolvedValue = configScope.getOptionalTransformed(
+        'value',
+        'def',
+        ensureClosingSlashTransformer,
+      )
+
+      expect(resolvedValue).toBe('def/')
+    })
   })
 
   describe('getMandatoryTransformed', () => {

src/config/ConfigScope.ts

@@ -67,7 +67,7 @@ export class ConfigScope {
     param: string,
     defaultValue: T,
   ): T | string {
-    return this.env[param] ?? defaultValue
+    return this.env[param] || defaultValue
   }
 
   getOptional(param: string, defaultValue: string): string {
@@ -118,7 +118,7 @@ export class ConfigScope {
     defaultValue: string,
     validator: EnvValueValidator<string>,
   ): string {
-    const value = this.env[param] ?? defaultValue
+    const value = this.env[param] || defaultValue
     if (!validator(value)) {
       throw new InternalError({
         message: `Value ${value} is invalid for parameter ${param}`,
@@ -150,7 +150,7 @@ export class ConfigScope {
     defaultValue: string,
     transformer: (value: string) => string,
   ): string {
-    const value = this.env[param] ?? defaultValue
+    const value = this.env[param] || defaultValue
     return transformer(value)
   }