Print attachment step text on error format

docs/support_files/attachments.md

@@ -81,3 +81,20 @@ After(function (testCase) {
   }
 });
 ```
+
+Attachments are also printed by the progress, progress-bar and summary formatter.
+They appears right after the step and only `text/plain` content is visible.
+It can be used to debug scenarios, especially in parallel mode.
+
+```
+// Step definition
+Given(/^a basic step$/, function() {
+  this.attach('Some info.')
+  this.attach('{"some", "JSON"}}', 'application/json')
+})
+
+// Result format
+✔ Given a basic step # path:line
+    Attachment (text/plain): Some info.
+    Attachment (application/json)
+```

features/error_formatting.feature

@@ -54,8 +54,8 @@ Feature: Error formatting
       """
       import {Given} from 'cucumber'
 
-      Given(/^a basic step$/, function() {})
-      Given(/^a step with a doc string$/, function(str) {})
+      Given(/^a basic step$/, function() { this.attach('Some info.') })
+      Given(/^a step with a doc string$/, function(str) { this.attach('{"name": "some JSON"}', 'application/json') })
       Given(/^a pending step$/, function() { return 'pending' })
       """
     When I run cucumber-js
@@ -65,10 +65,12 @@ Feature: Error formatting
 
       1) Scenario: some scenario # features/a.feature:3
          ✔ Given a basic step # features/step_definitions/cucumber_steps.js:3
+             Attachment (text/plain): Some info.
          ✔ And a step with a doc string # features/step_definitions/cucumber_steps.js:4
              \"\"\"
              my doc string
              \"\"\"
+             Attachment (application/json)
          ? And a pending step # features/step_definitions/cucumber_steps.js:5
              Pending
       """

src/formatter/helpers/issue_helpers.js

@@ -104,6 +104,14 @@ function formatStep({
       text += indentString(`${colorFn(str)}\n`, 4)
     }
   }
+
+  if (testStep.attachments) {
+    testStep.attachments.forEach(({ media, data }) => {
+      const message = media.type === 'text/plain' ? `: ${data}` : ''
+      text += indentString(`Attachment (${media.type})${message}\n`, 4)
+    })
+  }
+
   const message = getStepMessage({
     colorFns,
     keywordType,

src/formatter/helpers/issue_helpers_spec.js

@@ -235,5 +235,63 @@ describe('IssueHelpers', () => {
         )
       })
     })
+
+    describe('step with attachment text', () => {
+      beforeEach(function() {
+        this.testCase.steps[0].result = this.passedStepResult
+        this.testCase.steps[0].attachments = [
+          {
+            data: 'Some info.',
+            media: {
+              type: 'text/plain',
+            },
+          },
+          {
+            data: '{"name": "some JSON"}',
+            media: {
+              type: 'application/json',
+            },
+          },
+          {
+            data: Buffer.from([]),
+            media: {
+              type: 'image/png',
+            },
+          },
+        ]
+        this.testCase.steps[1] = {
+          actionLocation: { line: 3, uri: 'steps.js' },
+          sourceLocation: { line: 4, uri: 'a.feature' },
+          result: {
+            exception: 'error',
+            status: Status.FAILED,
+          },
+        }
+        this.testCase.steps[1].attachments = [
+          {
+            data: 'Other info.',
+            media: {
+              type: 'text/plain',
+            },
+          },
+        ]
+        this.testCase.steps[2].result = this.skippedStepResult
+        this.formattedIssue = formatIssue(this.options)
+      })
+
+      it('prints the scenario', function() {
+        expect(this.formattedIssue).to.eql(
+          '1) Scenario: my scenario # a.feature:2\n' +
+            `   ${figures.tick} Given step1 # steps.js:2\n` +
+            `       Attachment (text/plain): Some info.\n` +
+            `       Attachment (application/json)\n` +
+            `       Attachment (image/png)\n` +
+            `   ${figures.cross} When step2 # steps.js:3\n` +
+            `       Attachment (text/plain): Other info.\n` +
+            '       error\n' +
+            '   - Then step3 # steps.js:4\n\n'
+        )
+      })
+    })
   })
 })