Merge pull request #120 from vzamanillo/add-rule-description

Add rule description to the lint message marker tooltip

lib/linter-reek.js

@@ -2,6 +2,7 @@
 
 // eslint-disable-next-line import/no-extraneous-dependencies, import/extensions
 import { CompositeDisposable } from 'atom';
+import * as RuleHelpers from './rule-helpers';
 
 let helpers;
 let path;
@@ -99,11 +100,13 @@ export default {
         let match = parseRegex.exec(output);
         while (match !== null) {
           const line = Number.parseInt(match[1], 10) - 1;
-          const ruleLink = `https://github.com/troessner/reek/blob/master/docs/${match[3]}.md`;
+          const rule = match[3];
+          const ruleLink = `https://github.com/troessner/reek/blob/master/docs/${rule}.md`;
           messages.push({
             url: ruleLink,
+            description: () => RuleHelpers.getRuleMarkDown(rule),
             severity: 'warning',
-            excerpt: `${match[2]}`,
+            excerpt: match[2],
             location: {
               file: filePath,
               position: helpers.generateRange(TextEditor, line),

lib/rule-helpers.js

@@ -0,0 +1,59 @@
+'use babel';
+
+const DOCUMENTATION_LIFETIME = 86400 * 1000;
+const docsRuleCache = new Map();
+
+export function takeWhile(source, predicate) {
+  const result = [];
+  const { length } = source;
+  let i = 0;
+
+  while (i < length && predicate(source[i], i)) {
+    result.push(source[i]);
+    i += 1;
+  }
+
+  return result;
+}
+
+// Retrieves style guide documentation with cached responses
+export async function getRuleMarkDown(rule) {
+  if (docsRuleCache.has(rule)) {
+    const cachedRule = docsRuleCache.get(rule);
+    if (new Date().getTime() >= cachedRule.expires) {
+      // If documentation is stale, clear cache
+      docsRuleCache.delete(rule);
+    } else {
+      return cachedRule.markdown;
+    }
+  }
+
+  let rawRuleMarkdown;
+  const response = await fetch(`https://raw.githubusercontent.com/troessner/reek/master/docs/${rule}.md`);
+  if (response.ok) {
+    rawRuleMarkdown = await response.text();
+  } else {
+    return `***\nError retrieving documentation: ${response.statusText}`;
+  }
+
+  const byLine = rawRuleMarkdown.split('\n');
+  const ruleAnchors = byLine.reduce(
+    (acc, line, idx) => (line.match(/## Introduction/g) ? acc.concat(idx) : acc),
+    [],
+  );
+
+  ruleAnchors.forEach((startingIndex) => {
+    const beginSearch = byLine.slice(startingIndex + 1);
+
+    // gobble the introduction text until you reach the next section
+    const documentationForRule = takeWhile(beginSearch, x => !x.match(/##/));
+    const markdownOutput = '***\n'.concat(documentationForRule.join('\n'));
+
+    docsRuleCache.set(rule, {
+      markdown: markdownOutput,
+      expires: new Date().getTime() + DOCUMENTATION_LIFETIME,
+    });
+  });
+
+  return docsRuleCache.get(rule).markdown;
+}