Create local Error interface so that node doesn't need to be external…

…ly referenced (#1741)

src/configuration.ts

@@ -32,6 +32,14 @@ export interface IConfigurationFile {
     rules?: any;
 }
 
+/**
+ * Define `Error` here to avoid using `Error` from @types/node.
+ * Using the `node` version causes a compilation error when this code is used as an npm library if @types/node is not already imported.
+ */
+export interface Error {
+    message: string;
+}
+
 export interface IConfigurationLoadResult {
     error?: Error;
     path: string;

src/test/lintError.ts

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+import { Error } from "../configuration";
+
 export interface PositionInFile {
    line: number;
    col: number;
@@ -40,5 +42,5 @@ export function errorComparator(err1: LintError, err2: LintError) {
 }
 
 export function lintSyntaxError(message: string) {
-    return new Error(`Lint File Syntax Error: ${message}`);
+    return new Error(`Lint File Syntax Error: ${message}`) as Error;
 }