From 749b6d8dd0de2e431a9becb2ed0a590dd520426a Mon Sep 17 00:00:00 2001
From: ostridm <dmitry.ostrikov@brightsec.com>
Date: Thu, 14 Sep 2023 17:47:48 +0300
Subject: [PATCH] fix(sampler): introduce max-length support for string pattern
 format sample (#209)

closes #208
---
 .../src/samplers/StringSampler.ts             |  8 ++-
 packages/openapi-sampler/tests/string.spec.ts | 55 +++++++++++++++++++
 2 files changed, 60 insertions(+), 3 deletions(-)

diff --git a/packages/openapi-sampler/src/samplers/StringSampler.ts b/packages/openapi-sampler/src/samplers/StringSampler.ts
index 8a80b33a..678da90f 100644
--- a/packages/openapi-sampler/src/samplers/StringSampler.ts
+++ b/packages/openapi-sampler/src/samplers/StringSampler.ts
@@ -31,9 +31,9 @@ export class StringSampler implements Sampler {
     'regex': () => '/regex/',
     'pattern': (
       _min: number,
-      _max: number,
+      max: number,
       { pattern }: { pattern: string | RegExp }
-    ) => this.patternSample(pattern),
+    ) => this.patternSample(pattern, max),
     'default': (min: number, max: number) =>
       this.adjustLength('lorem', min, max)
   };
@@ -47,8 +47,10 @@ export class StringSampler implements Sampler {
     return this.checkLength(sampler(min || 0, max, schema), format, min, max);
   }
 
-  private patternSample(pattern: string | RegExp): string {
+  private patternSample(pattern: string | RegExp, max?: number): string {
     const randExp = new RandExp(pattern);
+
+    randExp.max = max ?? randExp.max;
     randExp.randInt = (a, b) => Math.floor((a + b) / 2);
 
     return randExp.gen();
diff --git a/packages/openapi-sampler/tests/string.spec.ts b/packages/openapi-sampler/tests/string.spec.ts
index 79101d11..c5bc24b5 100644
--- a/packages/openapi-sampler/tests/string.spec.ts
+++ b/packages/openapi-sampler/tests/string.spec.ts
@@ -24,6 +24,51 @@ describe('StringSampler', () => {
       },
       expected: '44'
     },
+    {
+      input: {
+        type: 'string',
+        format: 'pattern',
+        pattern: '^[a-z\\u05D0-\\u05EAA-Z0-9-/\\\\.\\u05F4,\'":&#;+()\\s]*$',
+        maxLength: 50
+      },
+      expected: 'MMMMMMMMMMMMMMMMMMMMMMMMM'
+    },
+    {
+      input: {
+        type: 'string',
+        format: 'pattern',
+        pattern: '^[A-Z0-9]*$',
+        maxLength: 10
+      },
+      expected: 'RRRRR'
+    },
+    {
+      input: {
+        type: 'string',
+        format: 'pattern',
+        pattern: '^[A-Z0-9]{1,15}$',
+        maxLength: 10
+      },
+      expected: 'RRRRRRRR'
+    },
+    {
+      input: {
+        type: 'string',
+        format: 'pattern',
+        pattern: '^\\w{5,5}\\d{5,5}$',
+        maxLength: 10
+      },
+      expected: 'EEEEE44444'
+    },
+    {
+      input: {
+        type: 'string',
+        format: 'pattern',
+        pattern: '^[A-Z0-9]*$',
+        maxLength: 0
+      },
+      expected: ''
+    },
     {
       input: {
         type: 'string',
@@ -221,6 +266,16 @@ describe('StringSampler', () => {
       expected:
         'Sample string cannot be generated by boundaries: maxLength=5, format=pattern'
     },
+    {
+      input: {
+        type: 'string',
+        format: 'pattern',
+        pattern: '^\\w{5,5}\\d{5,5}$',
+        maxLength: 9
+      },
+      expected:
+        'Sample string cannot be generated by boundaries: maxLength=9, format=pattern'
+    },
     {
       input: {
         type: 'string',