Add tests for the language service diagnostics

src/ServiceHost/Workspace/ScriptFile.cs

@@ -106,6 +106,13 @@ namespace Microsoft.SqlTools.EditorServices
 
         #region Constructors
 
+        /// <summary>
+        /// Add a default constructor for testing
+        /// </summary>
+        public ScriptFile()
+        {
+        }
+
         /// <summary>
         /// Creates a new ScriptFile instance by reading file contents from
         /// the given TextReader.
@@ -433,11 +440,11 @@ namespace Microsoft.SqlTools.EditorServices
             return new BufferRange(startPosition, endPosition);
         }
 
-        #endregion
-
-        #region Private Methods
-
-        private void SetFileContents(string fileContents)
+        /// <summary>
+        /// Set the script files contents
+        /// </summary>
+        /// <param name="fileContents"></param>
+        public void SetFileContents(string fileContents)
         {
             // Split the file contents into lines and trim
             // any carriage returns from the strings.
@@ -451,6 +458,10 @@ namespace Microsoft.SqlTools.EditorServices
             this.ParseFileContents();
         }
 
+        #endregion
+
+        #region Private Methods
+
         /// <summary>
         /// Parses the current file contents to get the AST, tokens,
         /// and parse errors.

test/ServiceHost.Test/LanguageServer/LanguageServiceTests.cs

@@ -0,0 +1,116 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.EditorServices;
+using Microsoft.SqlTools.EditorServices.Session;
+using Microsoft.SqlTools.LanguageSupport;
+using Xunit;
+
+namespace Microsoft.SqlTools.Test.LanguageServer
+{
+    /// <summary>
+    /// Tests for the ServiceHost Language Service tests
+    /// </summary>
+    public class LanguageServiceTests
+    {
+        /// <summary>
+        /// Create a test language service instance
+        /// </summary>
+        /// <returns></returns>
+        private LanguageService CreateTestService()
+        {
+            return new LanguageService(new SqlToolsContext(null, null));
+        }
+
+        #region "Diagnostics tests"
+
+        /// <summary>
+        /// Verify that the SQL parser correctly detects errors in text
+        /// </summary>
+        [Fact]
+        public void ParseSelectStatementWithoutErrors()
+        {
+            // sql statement with no errors
+            const string sqlWithErrors = "SELECT * FROM sys.objects";
+
+            // get the test service 
+            LanguageService service = CreateTestService();
+
+            // parse the sql statement
+            var scriptFile = new ScriptFile();
+            scriptFile.SetFileContents(sqlWithErrors);
+            ScriptFileMarker[] fileMarkers = service.GetSemanticMarkers(scriptFile);
+
+            // verify there are no errors
+            Assert.Equal(0, fileMarkers.Length);
+        }
+
+        /// <summary>
+        /// Verify that the SQL parser correctly detects errors in text
+        /// </summary>
+        [Fact]
+        public void ParseSelectStatementWithError()
+        {
+            // sql statement with errors
+            const string sqlWithErrors = "SELECT *** FROM sys.objects";
+
+            // get test service
+            LanguageService service = CreateTestService();
+
+            // parse sql statement
+            var scriptFile = new ScriptFile();
+            scriptFile.SetFileContents(sqlWithErrors);
+            ScriptFileMarker[] fileMarkers = service.GetSemanticMarkers(scriptFile);
+
+            // verify there is one error
+            Assert.Equal(1, fileMarkers.Length);
+
+            // verify the position of the error
+            Assert.Equal(9, fileMarkers[0].ScriptRegion.StartColumnNumber);
+            Assert.Equal(1, fileMarkers[0].ScriptRegion.StartLineNumber);
+            Assert.Equal(10, fileMarkers[0].ScriptRegion.EndColumnNumber);
+            Assert.Equal(1, fileMarkers[0].ScriptRegion.EndLineNumber);
+        }
+
+        /// <summary>
+        /// Verify that the SQL parser correctly detects errors in text
+        /// </summary>
+        [Fact]
+        public void ParseMultilineSqlWithErrors()
+        {
+            // multiline sql with errors
+            const string sqlWithErrors = 
+                "SELECT *** FROM sys.objects;\n" +
+                "GO\n" +
+                "SELECT *** FROM sys.objects;\n";
+
+            // get test service
+            LanguageService service = CreateTestService();
+
+            // parse sql
+            var scriptFile = new ScriptFile();
+            scriptFile.SetFileContents(sqlWithErrors);
+            ScriptFileMarker[] fileMarkers = service.GetSemanticMarkers(scriptFile);
+
+            // verify there are two errors
+            Assert.Equal(2, fileMarkers.Length);
+
+            // check position of first error
+            Assert.Equal(9, fileMarkers[0].ScriptRegion.StartColumnNumber);
+            Assert.Equal(1, fileMarkers[0].ScriptRegion.StartLineNumber);
+            Assert.Equal(10, fileMarkers[0].ScriptRegion.EndColumnNumber);
+            Assert.Equal(1, fileMarkers[0].ScriptRegion.EndLineNumber);
+
+            // check position of second error
+            Assert.Equal(9, fileMarkers[1].ScriptRegion.StartColumnNumber);
+            Assert.Equal(3, fileMarkers[1].ScriptRegion.StartLineNumber);
+            Assert.Equal(10, fileMarkers[1].ScriptRegion.EndColumnNumber);
+            Assert.Equal(3, fileMarkers[1].ScriptRegion.EndLineNumber);
+        }
+
+        #endregion
+    }
+}
+