1 files changed, 134 insertions, 0 deletions
diff --git a/js/where/where.test.js b/js/where/where.test.js
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+++ b/js/where/where.test.js
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+/**
+ * Simple test runner for the where function
+ */
+const test = {
+    run(name, fn) {
+        try {
+            fn();
+            console.log(`✅ ${name}`);
+        } catch (error) {
+            console.error(`❌ ${name}`);
+            console.error(error);
+        }
+    },
+
+    assertEquals(actual, expected, message = '') {
+        const actualStr = JSON.stringify(actual);
+        const expectedStr = JSON.stringify(expected);
+        if (actualStr !== expectedStr) {
+            throw new Error(`${message}\nExpected: ${expectedStr}\nReceived: ${actualStr}`);
+        }
+    }
+};
+
+// Test Data
+const testData = [
+    {
+        name: 'John',
+        age: 30,
+        hobbies: ['reading', 'music'],
+        address: {
+            city: 'New York',
+            country: 'USA'
+        },
+        preferences: {
+            theme: 'dark',
+            notifications: { email: true, sms: false }
+        }
+    },
+    {
+        name: 'Jane',
+        age: 25,
+        hobbies: ['sports'],
+        address: {
+            city: 'London',
+            country: 'UK'
+        },
+        preferences: {
+            theme: 'light',
+            notifications: { email: false, sms: true }
+        }
+    },
+    {
+        name: 'Bob',
+        age: 30,
+        hobbies: ['reading', 'music'],
+        address: {
+            city: 'New York',
+            country: 'USA'
+        },
+        preferences: {
+            theme: 'dark',
+            notifications: { email: true, sms: true }
+        }
+    }
+];
+
+// Basic Tests
+test.run('should handle empty inputs', () => {
+    test.assertEquals(where([], {}), [], 'Empty array and empty object');
+    test.assertEquals(where(null, {}), [], 'Null collection');
+    test.assertEquals(where(undefined, {}), [], 'Undefined collection');
+    test.assertEquals(where(testData, null), [], 'Null properties');
+});
+
+test.run('should match simple properties', () => {
+    const result = where(testData, { age: 30 });
+    test.assertEquals(result.length, 2, 'Should find two 30-year-olds');
+    test.assertEquals(
+        result.map(p => p.name),
+        ['John', 'Bob'],
+        'Should find John and Bob'
+    );
+});
+
+test.run('should match nested objects', () => {
+    const result = where(testData, {
+        address: { city: 'New York', country: 'USA' }
+    });
+    test.assertEquals(result.length, 2, 'Should find two New Yorkers');
+});
+
+test.run('should match arrays exactly', () => {
+    const result = where(testData, {
+        hobbies: ['reading', 'music']
+    });
+    test.assertEquals(result.length, 2, 'Should find two people with exact hobbies match');
+});
+
+test.run('should match deeply nested properties', () => {
+    const result = where(testData, {
+        preferences: { notifications: { email: true } }
+    });
+    test.assertEquals(result.length, 2, 'Should find two people with email notifications');
+});
+
+test.run('should handle multiple criteria', () => {
+    const result = where(testData, {
+        age: 30,
+        'preferences.theme': 'dark',
+        'address.city': 'New York'
+    });
+    test.assertEquals(result.length, 2, 'Should find people matching all criteria');
+});
+
+test.run('should return empty array for non-matching criteria', () => {
+    const result = where(testData, {
+        age: 99
+    });
+    test.assertEquals(result, [], 'Should return empty array for non-matching criteria');
+});
+
+test.run('should handle null values correctly', () => {
+    const dataWithNull = [...testData, { name: 'Alice', age: null }];
+    const result = where(dataWithNull, { age: null });
+    test.assertEquals(result.length, 1, 'Should find one person with null age');
+    test.assertEquals(result[0].name, 'Alice', 'Should find Alice');
+});
+
+// Run in Node.js environment
+if (typeof module !== 'undefined' && module.exports) {
+    module.exports = { test };
+}
+
+process.stdout.setEncoding('utf8'); 
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