feat: setting comments and adding non-existing entries

README.md

@@ -0,0 +1,26 @@
+# .env File Entries Manager
+
+This package allows you to easily manage `.env` file entries in a type-safe manner.
+
+## Usage
+
+```ts
+
+let dotEnv = new DotEnv(`EXAMPLE_NUMBER_FIELD=123`);
+
+// retrieving 
+const exampleNumberEntry = dotEnv.get<number>('EXAMPLE_NUMBER_FIELD');
+
+console.log(exampleNumberEntry.key); // string ("EXAMPLE_NUMBER_FIELD")
+console.log(exampleNumberEntry.value); // number (123)
+console.log(exampleNumberEntry.comment); // undefined
+
+// setting values and comments
+dotEnv.set('EXAMPLE_NUMBER_FIELD', 456);
+dotEnv.setComment('EXAMPLE_NUMBER_FIELD', 'Example comment');
+
+dotEnv.set('NEW_FIELD', 'test');
+
+// formatting entries to string
+console.log(dotEnv.toString()); // "EXAMPLE_NUMBER_FIELD=456 # Example comment\nNEWFIELD=test"
+```

src/dotEnv.ts

@@ -30,14 +30,30 @@ export class DotEnv {
         return this.entries.find((entry) => entry.key === key) as DotEnvEntry<T>;
     }
 
-    public set<T extends DotEnvEntryValueType>(key: string, value: DotEnvEntryValueType): DotEnvEntry<T> {
+    public set<T extends DotEnvEntryValueType>(key: string, value: T, comment?: string): DotEnvEntry<T> {
+        let entryIndex = this.entries.findIndex((entry) => entry.key === key);
+
+        if (entryIndex < 0) {
+            const entry = new DotEnvEntry(key, value, comment);
+
+            this.entries.push(entry);
+
+            return entry;
+        } else {
+            this.entries[entryIndex].value = value;
+
+            return this.entries[entryIndex] as DotEnvEntry<T>;
+        }
+    }
+
+    public setComment<T extends DotEnvEntryValueType>(key: string, comment: string | undefined): DotEnvEntry<T> {
         let entryIndex = this.entries.findIndex((entry) => entry.key === key);
 
         if (entryIndex < 0) {
             throw new Error(`Unable to find entry with the given key: ${key}`);
         }
 
-        this.entries[entryIndex].value = value;
+        this.entries[entryIndex].comment = comment;
 
         return this.entries[entryIndex] as DotEnvEntry<T>;
     }

src/dotEnvEntry.ts

@@ -1,9 +1,8 @@
 import {DotEnvEntryValueType} from "./dotEnvEntryValueType";
 
 export class DotEnvEntry<T = DotEnvEntryValueType> {
-    public key?: string;
-    public value?: T;
-    public comment?: string;
+    constructor(public key?: string, public value?: T, public comment?: string) {
+    }
 
     public toString(): string {
         let formattedEntry = '';

tests/dotEnv.test.ts

@@ -89,6 +89,31 @@ describe('DotEnv tests', () => {
         expect(updatedEntry?.value).toBe('updated');
     });
 
+    test('setting value and comment of a non-existing entry', () => {
+        const dotEnv = new DotEnv(`keyA=a`);
+
+        const addedEntry = dotEnv.set('NON_EXISTING', 'test-value', 'test-comment');
+
+        const entry = dotEnv.get('NON_EXISTING');
+
+        expect(entry?.value).toBe('test-value');
+        expect(addedEntry?.value).toBe('test-value');
+
+        expect(entry?.comment).toBe('test-comment');
+        expect(addedEntry?.comment).toBe('test-comment');
+    });
+
+    test('setting entry comment', () => {
+        const dotEnv = new DotEnv(`keyA=a`);
+
+        const updatedEntry = dotEnv.setComment('keyA', 'example comment');
+
+        const entry = dotEnv.get('keyA');
+
+        expect(entry?.comment).toBe('example comment');
+        expect(updatedEntry?.comment).toBe('example comment');
+    });
+
     test('removing an entry', () => {
         const dotEnv = new DotEnv(`keyA=a`);