tests(reader): Add snapshots to thrown errors

Author: Walker

test/__snapshots__/reader.test.js.snap

@@ -0,0 +1,12 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`new Reader(): throws on no input 1`] = `
+"Expected first argument to new Reader() to be a stream or array of streams. 
+            Instead got undefined"
+`;
+
+exports[`new Reader([]): throws on empty array 1`] = `"Expected at least one stream to be provided to new Reader(). Got none."`;
+
+exports[`new Reader([1,2,3]): throws on array containing non stream items 1`] = `"readStream.on is not a function"`;
+
+exports[`new Reader(123): throws on non stream or array input 1`] = `"readStream.on is not a function"`;

test/reader.test.js

@@ -155,25 +155,25 @@ test('Event: parse error', done => {
 test('new Reader(): throws on no input', () => {
     expect.assertions(1);
     const result = () => new Reader();
-    expect(result).toThrow();
+    expect(result).toThrowErrorMatchingSnapshot();
 });
 
 test('new Reader(123): throws on non stream or array input', () => {
     expect.assertions(1);
     const result = () => new Reader(123);
-    expect(result).toThrow();
+    expect(result).toThrowErrorMatchingSnapshot();
 });
 
 test('new Reader([]): throws on empty array', () => {
     expect.assertions(1);
     const result = () => new Reader([]);
-    expect(result).toThrow();
+    expect(result).toThrowErrorMatchingSnapshot();
 });
 
 test('new Reader([1,2,3]): throws on array containing non stream items', () => {
     expect.assertions(1);
     const result = () => new Reader([1, 2, 3]);
-    expect(result).toThrow();
+    expect(result).toThrowErrorMatchingSnapshot();
 });
 
 test('SortAndDedupe() rows without id value dropped', done => {