fix type errors in [DynamicXml] service (#4041)

* fix: type errors in DynamicXml service

* tests: add more tests for DynamicXml

* tests: another DynamicXml service test

services/dynamic/dynamic-xml.service.js

@@ -27,18 +27,11 @@ module.exports = class DynamicXml extends BaseService {
     }
   }
 
-  async handle(namedParams, { url, query: pathExpression, prefix, suffix }) {
+  transform({ pathExpression, buffer }) {
     // e.g. //book[2]/@id
     const pathIsAttr = (
       pathExpression.split('/').slice(-1)[0] || ''
     ).startsWith('@')
-
-    const { buffer } = await this._request({
-      url,
-      options: { headers: { Accept: 'application/xml, text/xml' } },
-      errorMessages,
-    })
-
     const parsed = new DOMParser().parseFromString(buffer)
 
     let values
@@ -47,14 +40,42 @@ module.exports = class DynamicXml extends BaseService {
     } catch (e) {
       throw new InvalidParameter({ prettyMessage: e.message })
     }
-    values = values.map((node, i) =>
-      pathIsAttr ? node.value : node.firstChild.data
-    )
+
+    if (!Array.isArray(values)) {
+      throw new InvalidResponse({
+        prettyMessage: 'unsupported query',
+      })
+    }
+
+    values = values.reduce((accum, node) => {
+      if (pathIsAttr) {
+        accum.push(node.value)
+      } else if (node.firstChild) {
+        accum.push(node.firstChild.data)
+      }
+
+      return accum
+    }, [])
 
     if (!values.length) {
       throw new InvalidResponse({ prettyMessage: 'no result' })
     }
 
-    return renderDynamicBadge({ value: values, prefix, suffix })
+    return { values }
+  }
+
+  async handle(_namedParams, { url, query: pathExpression, prefix, suffix }) {
+    const { buffer } = await this._request({
+      url,
+      options: { headers: { Accept: 'application/xml, text/xml' } },
+      errorMessages,
+    })
+
+    const { values: value } = this.transform({
+      pathExpression,
+      buffer,
+    })
+
+    return renderDynamicBadge({ value, prefix, suffix })
   }
 }

services/dynamic/dynamic-xml.spec.js

@@ -0,0 +1,31 @@
+'use strict'
+
+const { expect } = require('chai')
+const sinon = require('sinon')
+const xpath = require('xpath')
+const { exampleXml } = require('./dynamic-response-fixtures')
+const DynamicXml = require('./dynamic-xml.service')
+const { InvalidResponse } = require('..')
+
+describe('DynamicXml', function() {
+  describe('transform()', function() {
+    beforeEach(function() {
+      sinon.stub(xpath, 'select').returns(undefined)
+    })
+
+    afterEach(function() {
+      sinon.restore()
+    })
+
+    it('throws InvalidResponse on unsupported query', function() {
+      expect(() =>
+        DynamicXml.prototype.transform({
+          pathExpression: '//book/title',
+          buffer: exampleXml,
+        })
+      )
+        .to.throw(InvalidResponse)
+        .with.property('prettyMessage', 'unsupported query')
+    })
+  })
+})

services/dynamic/dynamic-xml.tester.js

@@ -176,3 +176,33 @@ t.create('request should set Accept header')
       .reply(200, exampleXml)
   )
   .expectBadge({ label: 'custom badge', message: 'Midnight Rain' })
+
+// https://github.com/badges/shields/issues/3814
+t.create('no result')
+  .get(
+    `.json?${queryString.stringify({
+      url: exampleUrl,
+      query: '//book[1]/title/text()',
+    })}`
+  )
+  .intercept(withExampleXml)
+  .expectBadge({
+    label: 'custom badge',
+    message: 'no result',
+    color: 'lightgrey',
+  })
+
+// https://github.com/badges/shields/issues/4017
+t.create('unsupported query')
+  .get(
+    `.json?${queryString.stringify({
+      url: exampleUrl,
+      query: 'string(//book[1]/title)',
+    })}`
+  )
+  .intercept(withExampleXml)
+  .expectBadge({
+    label: 'custom badge',
+    message: 'unsupported query',
+    color: 'lightgrey',
+  })