Add basic infrastructure, MD031, and test.

lib/markdownlint.js

@@ -0,0 +1,27 @@
+"use strict";
+
+var fs = require("fs");
+var rules = require("./rules");
+
+function lintFile(file, options) {
+  var results = {};
+  var contents = fs.readFileSync(file, { encoding: "utf8" });
+  var lines = contents.split(/\r\n|\n/g);
+  Object.keys(rules).forEach(function(name) {
+    var rule = rules[name];
+    var errors = rule(lines);
+    if (errors.length) {
+      results[name] = errors;
+    }
+  });
+  return results;
+}
+
+module.exports = function(options) {
+  var results = {};
+  var files = options.files || [];
+  files.forEach(function(file) {
+    results[file] = lintFile(file, options);
+  });
+  return results;
+};

lib/rules.js

@@ -0,0 +1,30 @@
+"use strict";
+
+function padAndTrim(lines) {
+  return [].concat(
+    "",
+    lines.map(function(line) {
+      return line.trim();
+    }),
+    "");
+}
+
+module.exports = {
+  MD031: function(lines) {
+    // Some parsers have trouble detecting fenced code blocks without
+    // surrounding whitespace, so examine the lines directly.
+    lines = padAndTrim(lines);
+    var errors = [];
+    var inCode = false;
+    lines.forEach(function(line, lineNum) {
+      if (line.match(/^(```|~~~)/)) {
+        inCode = !inCode;
+        if ((inCode && lines[lineNum - 1].length) ||
+            (!inCode && lines[lineNum + 1].length)) {
+          errors.push(lineNum);
+        }
+      }
+    });
+    return errors;
+  }
+};

package.json

@@ -2,7 +2,7 @@
   "name": "markdownlint",
   "version": "0.0.1",
   "description": "A linting tool for Markdown files",
-  "main": "markdownlint.js",
+  "main": "lib/markdownlint.js",
   "author": "David Anson (http://dlaa.me/)",
   "license": "MIT",
   "homepage": "https://github.com/DavidAnson/markdownlint",

test/fenced_code_without_blank_lines.md

@@ -0,0 +1,42 @@
+```
+code at start of file
+```
+
+text
+
+```ruby
+code
+```
+
+text
+``` {MD031}
+code
+``` {MD031}
+text
+
+```
+code
+``` {MD031}
+text
+
+text
+``` {MD031}
+code
+```
+
+text
+
+```js
+code
+code
+code
+```
+
+```html
+```
+
+text
+
+```
+code at end of file without newline
+```

test/markdownlint-test.js

@@ -0,0 +1,36 @@
+"use strict";
+
+var fs = require("fs");
+var path = require("path");
+var markdownlint = require("../lib/markdownlint");
+
+function createTestForFile(file) {
+  return function(test) {
+    test.expect(1);
+    var contents = fs.readFileSync(file, { encoding: "utf8" });
+    var lines = contents.split(/\r\n|\n/g);
+    var results = {};
+    lines.forEach(function(line, lineNum) {
+      var match = line.match(/\{(MD\d+)(?::(\d+))?\}/);
+      if (match) {
+        var rule = match[1];
+        var lines = results[rule] || [];
+        lines.push(lineNum + 1);
+        results[rule] = lines;
+      }
+    });
+    var actual = markdownlint({
+      files: [ file ]
+    });
+    var expected = {};
+    expected[file] = results;
+    test.deepEqual(actual, expected, "Line numbers are not correct.");
+    test.done();
+  };
+}
+
+fs.readdirSync(__dirname).forEach(function(file) {
+  if (file.match(/\.md$/)) {
+    module.exports[file] = createTestForFile(path.join(__dirname, file));
+  }
+});