test: add a test case for joepie91 use case

package.json

@@ -18,7 +18,8 @@
     "flow-runtime": "^0.2.1",
     "nearley": "^2.7.11",
     "regex-parser": "^2.2.5",
-    "scalpel": "^2.1.0"
+    "scalpel": "^2.1.0",
+    "sprintf-js": "^1.0.3"
   },
   "description": "DOM extraction expression evaluator.",
   "devDependencies": {

test/draper/queries/joepie91.js

@@ -0,0 +1,97 @@
+// @flow
+
+import test from 'ava';
+import {
+  sprintf
+} from 'sprintf-js';
+import surgeon from '../../../src';
+import type {
+  DenormalizedQueryType
+} from '../../../src/types';
+
+test('extracts a single value (expression string)', (t): void => {
+  let lastSelector;
+
+  const x = surgeon({
+    subroutines: {
+      captureSelector: (evaluator, selector) => {
+        lastSelector = selector;
+
+        return selector;
+      },
+      index: (evaluator, element) => {
+        // $FlowFixMe
+        return element.index() + 1;
+      },
+      rootSelect: (evaluator, selector) => {
+        // $FlowFixMe
+        const matches = lastSelector.find(selector);
+
+        if (matches.length !== 1) {
+          throw new Error('Unexpected result count.');
+        }
+
+        return matches;
+      },
+      sprintf: (evaluator, value, [format]) => {
+        return sprintf(format, value);
+      }
+    }
+  });
+
+  const subject = `
+  <h1>My shiny news site</h1>
+
+  <div class="left">
+    <ul>
+      <li><strong>Title</strong></li>
+      <li><a href="...">News article one</a></li>
+      <li><a href="...">News article two</a></li>
+      <li><a href="...">News article three</a></li>
+    </ul>
+  </div>
+
+  <div class="right">
+    <ul>
+      <li><strong>Date</strong></li>
+      <li>14 minutes ago</li>
+      <li>17 minutes ago</li>
+      <li>31 minutes ago</li>
+    </ul>
+  </div>
+  `;
+
+  const query: DenormalizedQueryType = [
+    'captureSelector',
+    'select .left',
+    {
+      articles: [
+        'select li:not(:first-child) {0,}',
+        {
+          date: 'index | sprintf ".right ul li:nth-child(%d)" | rootSelect | read property textContent',
+          title: 'select a | read property textContent'
+        }
+      ]
+    }
+  ];
+  const result = x(query, subject);
+
+  const expectedResult = {
+    articles: [
+      {
+        date: '14 minutes ago',
+        title: 'News article one'
+      },
+      {
+        date: '17 minutes ago',
+        title: 'News article two'
+      },
+      {
+        date: '31 minutes ago',
+        title: 'News article three'
+      }
+    ]
+  };
+
+  t.deepEqual(result, expectedResult);
+});