feat(cli-repl): print index update violations

packages/cli-repl/src/format-output.spec.ts

@@ -140,6 +140,19 @@ for (const colors of [ false, true ]) {
         expect(output).to.equal(
           '\rError: Something went wrong.\nResult: { nInserted: 0 }');
       });
+
+      it('provides violation info if present', () => {
+        const err = Object.assign(new Error('Something went wrong.'), {
+          violations: [{ ids: [1] }]
+        });
+        const output = stripAnsiColors(format({
+          value: err,
+          type: 'Error'
+        }));
+
+        expect(output).to.equal(
+          '\rError: Something went wrong.\nViolations: [ { ids: [ 1 ] } ]');
+      });
     });
 
     context('when the result is ShowDatabasesResult', () => {

packages/cli-repl/src/format-output.ts

@@ -199,6 +199,7 @@ function formatListCommands(output: Record<string, any>, options: FormatOptions)
   return tableEntries.join('\n\n');
 }
 
+// eslint-disable-next-line complexity
 export function formatError(error: Error, options: FormatOptions): string {
   let result = '';
   if (error.name) result += `\r${clr(error.name, 'mongosh:error', options)}: `;
@@ -231,6 +232,10 @@ export function formatError(error: Error, options: FormatOptions): string {
     result += `\n${clr(i18n.__('cli-repl.cli-repl.additionalErrorResult'), 'mongosh:additional-error-info', options)}: `;
     result += inspect((error as any).result, options);
   }
+  if ((error as any).violations) {
+    result += `\n${clr(i18n.__('cli-repl.cli-repl.additionalErrorViolations'), 'mongosh:additional-error-info', options)}: `;
+    result += inspect((error as any).violations, options);
+  }
 
   return result;
 }

packages/cli-repl/test/e2e.spec.ts

@@ -310,6 +310,45 @@ describe('e2e', function() {
         expect(shell.output).to.match(
           /multi update (only works with \$ operators|is not supported for replacement-style update)/);
       });
+      context('when creating unique index', () => {
+        skipIfServerVersion(testServer, '< 5.3');
+
+        afterEach(async() => {
+          await shell.executeLine('db.apples.drop()');
+        });
+
+        it('prints out violations for unique index creation', async() => {
+          await shell.executeLine(`db.apples.insertMany([
+            { type: 'Delicious', quantity: 12 },
+            { type: 'Macintosh', quantity: 13 },
+            { type: 'Delicious', quantity: 13 },
+            { type: 'Fuji', quantity: 15 },
+            { type: 'Washington', quantity: 10 }
+          ]);`);
+
+          await shell.executeLine('db.apples.createIndex({ type: 1 });');
+
+          await shell.executeLine(`db.runCommand({
+            collMod: 'apples',
+            index: {
+              keyPattern: { type: 1 },
+              prepareUnique: true
+            }
+          });`);
+
+          const result = await shell.executeLine(`db.runCommand({
+            collMod: 'apples',
+            index: {
+              keyPattern: { type: 1 },
+              unique: true
+            }
+          });`);
+
+          expect(result).to.match(/Violations\:/);
+          // Two duplicated ids
+          expect(result).to.match(/ids: \[\s+ObjectId.+?\s+?ObjectId.+?\s+\]/m);
+        });
+      });
     });
     it('throws multiline input with a single line string', async() => {
       // this is an unterminated string constant and should throw, since it does

packages/i18n/src/locales/en_US.ts

@@ -83,7 +83,8 @@ const translations: Catalog = {
         link: 'https://docs.mongodb.com/mongodb-shell/'
       },
       additionalErrorInfo: 'Additional information',
-      additionalErrorResult: 'Result'
+      additionalErrorResult: 'Result',
+      additionalErrorViolations: 'Violations'
     },
     'uri-generator': {
       'no-host-port': 'If a full URI is provided, you cannot also specify --host or --port',