RequestParserUnitTests.cs

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

using Azure.DataApiBuilder.Core.Parsers;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace Azure.DataApiBuilder.Service.Tests.UnitTests
{
    /// <summary>
    /// Test class for RequestParser utility methods.
    /// Specifically tests the ExtractRawQueryParameter method which preserves
    /// URL encoding for special characters in query parameters.
    /// </summary>
    [TestClass]
    public class RequestParserUnitTests
    {
        /// <summary>
        /// Tests that ExtractRawQueryParameter correctly extracts URL-encoded
        /// parameter values, preserving special characters like ampersand (&).
        /// </summary>
        [DataTestMethod]
        [DataRow("?$filter=region%20eq%20%27filter%20%26%20test%27", "$filter", "region%20eq%20%27filter%20%26%20test%27", DisplayName = "Extract filter with encoded ampersand (&)")]
        [DataRow("?$filter=title%20eq%20%27A%20%26%20B%27&$select=id", "$filter", "title%20eq%20%27A%20%26%20B%27", DisplayName = "Extract filter with ampersand and other params")]
        [DataRow("?$select=id&$filter=name%20eq%20%27test%27", "$filter", "name%20eq%20%27test%27", DisplayName = "Extract filter when not first parameter")]
        [DataRow("?$orderby=name%20asc", "$orderby", "name%20asc", DisplayName = "Extract orderby parameter")]
        [DataRow("?param1=value1&param2=value%26with%26ampersands", "param2", "value%26with%26ampersands", DisplayName = "Extract parameter with multiple ampersands")]
        [DataRow("$filter=title%20eq%20%27test%27", "$filter", "title%20eq%20%27test%27", DisplayName = "Extract without leading question mark")]
        [DataRow("?$filter=", "$filter", "", DisplayName = "Extract empty filter value")]
        [DataRow("?$filter=name%20eq%20%27test%3D123%27", "$filter", "name%20eq%20%27test%3D123%27", DisplayName = "Extract filter with encoded equals sign (=)")]
        [DataRow("?$filter=url%20eq%20%27http%3A%2F%2Fexample.com%3Fkey%3Dvalue%27", "$filter", "url%20eq%20%27http%3A%2F%2Fexample.com%3Fkey%3Dvalue%27", DisplayName = "Extract filter with encoded URL (: / ?)")]
        [DataRow("?$filter=text%20eq%20%27A%2BB%27", "$filter", "text%20eq%20%27A%2BB%27", DisplayName = "Extract filter with encoded plus sign (+)")]
        [DataRow("?$filter=value%20eq%20%2750%25%27", "$filter", "value%20eq%20%2750%25%27", DisplayName = "Extract filter with encoded percent sign (%)")]
        [DataRow("?$filter=tag%20eq%20%27%23hashtag%27", "$filter", "tag%20eq%20%27%23hashtag%27", DisplayName = "Extract filter with encoded hash (#)")]
        [DataRow("?$filter=expr%20eq%20%27a%3Cb%3Ed%27", "$filter", "expr%20eq%20%27a%3Cb%3Ed%27", DisplayName = "Extract filter with encoded less-than and greater-than (< >)")]
        public void ExtractRawQueryParameter_PreservesEncoding(string queryString, string parameterName, string expectedValue)
        {
            // Call the internal method directly (no reflection needed)
            string result = RequestParser.ExtractRawQueryParameter(queryString, parameterName);

            Assert.AreEqual(expectedValue, result,
                $"Expected '{expectedValue}' but got '{result}' for parameter '{parameterName}' in query '{queryString}'");
        }

        /// <summary>
        /// Tests that ExtractRawQueryParameter returns null when parameter is not found.
        /// </summary>
        [DataTestMethod]
        [DataRow("?$filter=test", "$orderby", DisplayName = "Parameter not in query string")]
        [DataRow("", "$filter", DisplayName = "Empty query string")]
        [DataRow(null, "$filter", DisplayName = "Null query string")]
        [DataRow("?otherParam=value", "$filter", DisplayName = "Different parameter")]
        public void ExtractRawQueryParameter_ReturnsNull_WhenParameterNotFound(string queryString, string parameterName)
        {
            // Call the internal method directly (no reflection needed)
            string result = RequestParser.ExtractRawQueryParameter(queryString, parameterName);

            Assert.IsNull(result,
                $"Expected null but got '{result}' for parameter '{parameterName}' in query '{queryString}'");
        }

        /// <summary>
        /// Tests that ExtractRawQueryParameter handles edge cases correctly:
        /// - Duplicate parameters (returns first occurrence)
        /// - Case-insensitive parameter name matching
        /// - Malformed query strings with unencoded ampersands
        /// </summary>
        [DataTestMethod]
        [DataRow("?$filter=value&$filter=anothervalue", "$filter", "value", DisplayName = "Multiple same parameters - returns first")]
        [DataRow("?$FILTER=value", "$filter", "value", DisplayName = "Case insensitive parameter matching")]
        [DataRow("?param=value1&value2", "param", "value1", DisplayName = "Value with unencoded ampersand after parameter")]
        public void ExtractRawQueryParameter_HandlesEdgeCases(string queryString, string parameterName, string expectedValue)
        {
            // Call the internal method directly (no reflection needed)
            string result = RequestParser.ExtractRawQueryParameter(queryString, parameterName);

            Assert.AreEqual(expectedValue, result,
                $"Expected '{expectedValue}' but got '{result}' for parameter '{parameterName}' in query '{queryString}'");
        }
    }
}