Corrects exception on diff command and removes redundant share operator

packages/cli/src/commands/diff.js

@@ -1,4 +1,4 @@
-import {_, observable} from '@report-toolkit/common';
+import {_} from '@report-toolkit/common';
 import {observable as observableAPI} from '@report-toolkit/core';
 
 import {terminalColumns, toOutput} from '../console-utils.js';
@@ -11,7 +11,6 @@ import {
 } from './common.js';
 
 const {diff, transform, fromTransformerChain} = observableAPI;
-const {share} = observable;
 
 const OP_COLORS = _.toFrozenMap({
   add: 'green',
@@ -120,11 +119,9 @@ export const handler = argv => {
   });
 
   const source = diff(
-    fromFilepathsToReports(file1).pipe(share()),
-    fromFilepathsToReports(file2).pipe(
-      share(),
-      config
-    )
+    fromFilepathsToReports(file1),
+    fromFilepathsToReports(file2),
+    config
   );
 
   fromTransformerChain(argv.transform, config)

packages/cli/test/e2e/diff.spec.js

@@ -0,0 +1,34 @@
+import {runWithOptions} from './cli-helper.js';
+
+const REPORT_001_FILEPATH = require.resolve(
+  '@report-toolkit/common/test/fixture/reports/report-001.json'
+);
+const REPORT_002_FILEPATH = require.resolve(
+  '@report-toolkit/common/test/fixture/reports/report-002-library-mismatch.json'
+);
+
+describe('@report-toolkit/cli:command:diff', function() {
+  describe('when run with a single report file', function() {
+    it('should exit with code 1', function() {
+      return expect(
+        runWithOptions(['diff', REPORT_001_FILEPATH]),
+        'to be rejected with error satisfying',
+        {
+          exitCode: 1
+        }
+      );
+    });
+  });
+
+  describe('when run with two report files', function() {
+    it('should exit with code 0', function() {
+      return expect(
+        runWithOptions(['diff', REPORT_001_FILEPATH, REPORT_002_FILEPATH]),
+        'to be fulfilled with value satisfying',
+        {
+          exitCode: 0
+        }
+      );
+    });
+  });
+});