Add symbol change API endpoint. (#41)

Fixes #38

Author: Matthiee

FinancialModelingPrepApi/Abstractions/CompanyValuation/ICompanyValuationProvider.cs

@@ -7,6 +7,13 @@ namespace MatthiWare.FinancialModelingPrep.Abstractions.CompanyValuation
 {
     public interface ICompanyValuationProvider
     {
+        /// <summary>
+        /// Public comapnies sometimes change their symbol and thanks to this endpoint you will be able to know if there is any symbol change happened. 
+        /// Data for new symbol is getting transferred from the old symbol the same day
+        /// </summary>
+        /// <returns></returns>
+        public Task<ApiResponse<List<SymbolChangeResponse>>> GetSymbolChangesAsync();
+
         public Task<ApiResponse<QuoteResponse>> GetQuoteAsync(string symbol);
         public Task<ApiResponse<List<QuoteResponse>>> GetQuotesAsync(IEnumerable<string> symbols);
         public Task<ApiResponse<List<QuoteResponse>>> GetQuotesAsync(Exchange exchange);

FinancialModelingPrepApi/Core/CompanyValuation/CompanyValuationProvider.cs

@@ -552,5 +552,19 @@ public Task<ApiResponse<List<PressReleasesResponse>>> GetPressReleasesAsync(stri
 
             return client.GetJsonAsync<List<PressReleasesResponse>>(url, pathParams, queryString);
         }
+
+        /// <inheritdoc />
+        public Task<ApiResponse<List<SymbolChangeResponse>>> GetSymbolChangesAsync()
+        {
+            const string url = "[version]/symbol_change";
+
+            var pathParams = new NameValueCollection()
+            {
+                { "version", ApiVersion.v4.ToString() }
+            };
+
+            return client.GetJsonAsync<List<SymbolChangeResponse>>(url, pathParams, null);
+
+        }
     }
 }

FinancialModelingPrepApi/Model/CompanyValuation/SymbolChangeResponse.cs

@@ -0,0 +1,19 @@
+using System.Text.Json.Serialization;
+
+namespace MatthiWare.FinancialModelingPrep.Model.CompanyValuation
+{
+    public class SymbolChangeResponse
+    {
+        [JsonPropertyName("date")]
+        public string Date { get; set; }
+
+        [JsonPropertyName("name")]
+        public string Name { get; set; }
+
+        [JsonPropertyName("oldSymbol")]
+        public string OldSymbol { get; set; }
+
+        [JsonPropertyName("newSymbol")]
+        public string NewSymbol { get; set; }
+    }
+}

Tests/CompanyValuation/CompanyValuationTests.cs

@@ -21,6 +21,16 @@ public CompanyValuationTests(ITestOutputHelper testOutput) : base(testOutput)
             api = ServiceProvider.GetRequiredService<ICompanyValuationProvider>();
         }
 
+
+        [Fact]
+        public async Task GetSymbolChangesAsyncTests()
+        {
+            var result = await api.GetSymbolChangesAsync();
+
+            result.AssertNoErrors();
+            Assert.NotEmpty(result.Data);
+        }
+
         [Theory]
         [InlineData("AAPL")]
         [InlineData("SPY")]