From 406c08f26d6012f55c575d00094b4d40a8931bf4 Mon Sep 17 00:00:00 2001
From: Benedikt Franke <benedikt.franke@mll.com>
Date: Mon, 22 Apr 2024 09:43:20 +0200
Subject: [PATCH] feat: add isNonEmptyString

---
 package.json           |  2 +-
 src/typeGuards.test.ts | 18 +++++++++++++++++-
 src/typeGuards.ts      |  9 +++++----
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/package.json b/package.json
index 48e8dcf..cf99012 100644
--- a/package.json
+++ b/package.json
@@ -79,5 +79,5 @@
     "ts-node": "^9.1.1",
     "typescript": "^5.3.3"
   },
-  "packageManager": "yarn@4.1.0"
+  "packageManager": "yarn@4.1.1"
 }
diff --git a/src/typeGuards.test.ts b/src/typeGuards.test.ts
index dc14d1f..7ddaec3 100644
--- a/src/typeGuards.test.ts
+++ b/src/typeGuards.test.ts
@@ -1,7 +1,23 @@
 import { assertFalse, assertTrue } from './predicates.test';
-import { isArrayOfStrings, isEmptyObject, isNotNullish } from './typeGuards';
+import {
+  isArrayOfStrings,
+  isEmptyObject,
+  isNonEmptyString,
+  isNotNullish,
+  isString,
+} from './typeGuards';
 
 describe('typeGuards', () => {
+  describe('isString', () => {
+    assertTrue(isString, ['foo', '1', 'true', '']);
+    assertFalse(isString, [/foo/, 1, true, null, undefined]);
+  });
+
+  describe('isNonEmptyString', () => {
+    assertTrue(isNonEmptyString, ['foo', '1', 'true']);
+    assertFalse(isNonEmptyString, ['', /foo/, 1, true, null, undefined]);
+  });
+
   describe('isNotNullish', () => {
     assertTrue(isNotNullish, ['', [], {}, false]);
     assertFalse(isNotNullish, [null, undefined]);
diff --git a/src/typeGuards.ts b/src/typeGuards.ts
index 59155f1..9432c3a 100644
--- a/src/typeGuards.ts
+++ b/src/typeGuards.ts
@@ -2,15 +2,16 @@ export function isString(value: unknown): value is string {
   return typeof value === 'string';
 }
 
+export function isNonEmptyString(value: unknown): value is Exclude<string, ''> {
+  return isString(value) && value !== '';
+}
+
 export function isNotNullish<T>(value: T): value is NonNullable<T> {
   return value != null;
 }
 
 export function isArrayOfStrings(value: unknown): value is Array<string> {
-  return (
-    value instanceof Array &&
-    value.every((record) => typeof record === 'string')
-  );
+  return value instanceof Array && value.every(isString);
 }
 
 export function isEmptyObject(value: unknown): value is Record<string, never> {