Add support for using custom rules.

.eslintrc.json

@@ -63,7 +63,7 @@
         "max-len": "error",
         "max-lines": "off",
         "max-nested-callbacks": "error",
-        "max-params": ["error", 7],
+        "max-params": ["error", 8],
         "max-statements": ["error", 20],
         "max-statements-per-line": "error",
         "multiline-comment-style": ["error", "separate-lines"],

README.md

@@ -184,6 +184,26 @@ Type: `Object`
 
 Configures the function.
 
+##### options.customRules
+
+Type: `Array` of `Object`
+
+List of custom rules to include with the default rule set for linting.
+
+Each array element should define a rule. Rules are typically exported by another
+package, but can be defined inline.
+
+Example:
+
+```js
+var extraRules = require("extraRules");
+var options = {
+  "customRules": [ extraRules.one, extraRules.two ]
+};
+```
+
+See [CustomRules.md](doc/CustomRules.md) for details about authoring custom rules.
+
 ##### options.files
 
 Type: `Array` of `String`
@@ -316,7 +336,8 @@ The default value:
 /^(---|\+\+\+)$[^]*?^\1$(\r\n|\r|\n)/m
 ```
 
-Ignores [YAML](https://en.wikipedia.org/wiki/YAML) and [TOML](https://en.wikipedia.org/wiki/TOML) such as:
+Ignores [YAML](https://en.wikipedia.org/wiki/YAML) and
+[TOML](https://en.wikipedia.org/wiki/TOML) such as:
 
 ```text
 ---

doc/CustomRules.md

@@ -0,0 +1 @@
+# TBD

lib/markdownlint.js

@@ -9,54 +9,58 @@ var rules = require("./rules");
 var shared = require("./shared");
 
 // Class for results with toString for pretty display
-function Results() {}
-Results.prototype.toString = function resultsToString(useAlias) {
-  var that = this;
-  var ruleNameToRule = null;
-  var results = [];
-  Object.keys(that).forEach(function forFile(file) {
-    var fileResults = that[file];
-    if (Array.isArray(fileResults)) {
-      fileResults.forEach(function forResult(result) {
-        var ruleMoniker = result.ruleNames ?
-          result.ruleNames.join("/") :
-          (result.ruleName + "/" + result.ruleAlias);
-        results.push(
-          file + ": " +
-          result.lineNumber + ": " +
-          ruleMoniker + " " +
-          result.ruleDescription +
-          (result.errorDetail ?
-            " [" + result.errorDetail + "]" :
-            "") +
-          (result.errorContext ?
-            " [Context: \"" + result.errorContext + "\"]" :
-            ""));
-      });
-    } else {
-      if (!ruleNameToRule) {
-        ruleNameToRule = {};
-        rules.forEach(function forRule(rule) {
-          var ruleName = rule.names[0].toUpperCase();
-          ruleNameToRule[ruleName] = rule;
+function newResults(ruleSet) {
+  function Results() {}
+  Results.prototype.toString = function resultsToString(useAlias) {
+    var that = this;
+    var ruleNameToRule = null;
+    var results = [];
+    Object.keys(that).forEach(function forFile(file) {
+      var fileResults = that[file];
+      if (Array.isArray(fileResults)) {
+        fileResults.forEach(function forResult(result) {
+          var ruleMoniker = result.ruleNames ?
+            result.ruleNames.join("/") :
+            (result.ruleName + "/" + result.ruleAlias);
+          results.push(
+            file + ": " +
+            result.lineNumber + ": " +
+            ruleMoniker + " " +
+            result.ruleDescription +
+            (result.errorDetail ?
+              " [" + result.errorDetail + "]" :
+              "") +
+            (result.errorContext ?
+              " [Context: \"" + result.errorContext + "\"]" :
+              ""));
+        });
+      } else {
+        if (!ruleNameToRule) {
+          ruleNameToRule = {};
+          ruleSet.forEach(function forRule(rule) {
+            var ruleName = rule.names[0].toUpperCase();
+            ruleNameToRule[ruleName] = rule;
+          });
+        }
+        Object.keys(fileResults).forEach(function forRule(ruleName) {
+          var rule = ruleNameToRule[ruleName.toUpperCase()];
+          var ruleResults = fileResults[ruleName];
+          ruleResults.forEach(function forLine(lineNumber) {
+            var nameIndex = Math.min(useAlias ? 1 : 0, rule.names.length - 1);
+            var result =
+              file + ": " +
+              lineNumber + ": " +
+              rule.names[nameIndex] + " " +
+              rule.description;
+            results.push(result);
+          });
         });
       }
-      Object.keys(fileResults).forEach(function forRule(ruleName) {
-        var rule = ruleNameToRule[ruleName];
-        var ruleResults = fileResults[ruleName];
-        ruleResults.forEach(function forLine(lineNumber) {
-          var result =
-            file + ": " +
-            lineNumber + ": " +
-            rule.names[useAlias ? 1 : 0] + " " +
-            rule.description;
-          results.push(result);
-        });
-      });
-    }
-  });
-  return results.join("\n");
-};
+    });
+    return results.join("\n");
+  };
+  return new Results();
+}
 
 // Remove front matter (if present at beginning of content)
 function removeFrontMatter(content, frontMatter) {
@@ -151,16 +155,16 @@ function mapAliasToRuleNames(ruleList) {
   return aliasToRuleNames;
 }
 
-// Merge rules/tags and sanitize config
-function mergeRulesAndSanitize(config, aliasToRuleNames) {
+// Apply (and normalize) config
+function getEffectiveConfig(ruleSet, config, aliasToRuleNames) {
   var defaultKey = Object.keys(config).filter(function forKey(key) {
     return key.toUpperCase() === "DEFAULT";
   });
   var ruleDefault = (defaultKey.length === 0) || !!config[defaultKey[0]];
-  var mergedRules = {};
-  rules.forEach(function forRule(rule) {
+  var effectiveConfig = {};
+  ruleSet.forEach(function forRule(rule) {
     var ruleName = rule.names[0].toUpperCase();
-    mergedRules[ruleName] = ruleDefault;
+    effectiveConfig[ruleName] = ruleDefault;
   });
   Object.keys(config).forEach(function forKey(key) {
     var value = config[key];
@@ -173,21 +177,22 @@ function mergeRulesAndSanitize(config, aliasToRuleNames) {
     }
     var keyUpper = key.toUpperCase();
     (aliasToRuleNames[keyUpper] || []).forEach(function forRule(ruleName) {
-      mergedRules[ruleName] = value;
+      effectiveConfig[ruleName] = value;
     });
   });
-  return mergedRules;
+  return effectiveConfig;
 }
 
 // Create mapping of enabled rules per line
 function getEnabledRulesPerLineNumber(
-  lines, frontMatterLines, noInlineConfig, mergedRules, aliasToRuleNames) {
+  ruleSet, lines, frontMatterLines, noInlineConfig,
+  effectiveConfig, aliasToRuleNames) {
   var enabledRules = {};
   var allRuleNames = [];
-  rules.forEach(function forRule(rule) {
+  ruleSet.forEach(function forRule(rule) {
     var ruleName = rule.names[0].toUpperCase();
     allRuleNames.push(ruleName);
-    enabledRules[ruleName] = !!mergedRules[ruleName];
+    enabledRules[ruleName] = !!effectiveConfig[ruleName];
   });
   function forMatch(match) {
     var enabled = match[1].toUpperCase() === "EN";
@@ -229,7 +234,7 @@ function uniqueFilterForSortedErrors(value, index, array) {
 
 // Lints a single string
 function lintContent(
-  content, config, frontMatter, noInlineConfig, resultVersion) {
+  ruleSet, content, config, frontMatter, noInlineConfig, resultVersion) {
   // Remove UTF-8 byte order marker (if present)
   if (content.charCodeAt(0) === 0xfeff) {
     content = content.slice(1);
@@ -244,10 +249,11 @@ function lintContent(
   var tokens = md.parse(content, {});
   var lines = content.split(shared.newLineRe);
   var tokenLists = annotateTokens(tokens, lines);
-  var aliasToRuleNames = mapAliasToRuleNames(rules);
-  var mergedRules = mergeRulesAndSanitize(config, aliasToRuleNames);
+  var aliasToRuleNames = mapAliasToRuleNames(ruleSet);
+  var effectiveConfig = getEffectiveConfig(ruleSet, config, aliasToRuleNames);
   var enabledRulesPerLineNumber = getEnabledRulesPerLineNumber(
-    lines, frontMatterLines, noInlineConfig, mergedRules, aliasToRuleNames);
+    ruleSet, lines, frontMatterLines, noInlineConfig,
+    effectiveConfig, aliasToRuleNames);
   // Create parameters for rules
   var params = {
     "tokens": tokens,
@@ -257,10 +263,11 @@ function lintContent(
   };
   // Run each rule
   var result = (resultVersion === 0) ? {} : [];
-  rules.forEach(function forRule(rule) {
+  ruleSet.forEach(function forRule(rule) {
     // Configure rule
-    var ruleName = rule.names[0].toUpperCase();
-    params.config = mergedRules[ruleName];
+    var ruleNameFriendly = rule.names[0];
+    var ruleName = ruleNameFriendly.toUpperCase();
+    params.config = effectiveConfig[ruleName];
     var errors = [];
     function onError(errorInfo) {
       errors.push({
@@ -286,8 +293,8 @@ function lintContent(
           var errorObject = {};
           errorObject.lineNumber = error.lineNumber;
           if (resultVersion === 1) {
-            errorObject.ruleName = rule.names[0];
-            errorObject.ruleAlias = rule.names[1];
+            errorObject.ruleName = ruleNameFriendly;
+            errorObject.ruleAlias = rule.names[1] || rule.names[0];
           } else {
             errorObject.ruleNames = rule.names;
           }
@@ -299,9 +306,9 @@ function lintContent(
         });
       if (filteredErrors.length) {
         if (resultVersion === 0) {
-          result[ruleName] = filteredErrors;
+          result[ruleNameFriendly] = filteredErrors;
         } else {
-          result.push.apply(result, filteredErrors);
+          Array.prototype.push.apply(result, filteredErrors);
         }
       }
     }
@@ -311,6 +318,7 @@ function lintContent(
 
 // Lints a single file
 function lintFile(
+  ruleSet,
   file,
   config,
   frontMatter,
@@ -323,7 +331,7 @@ function lintFile(
       return callback(err);
     }
     var result = lintContent(
-      content, config, frontMatter, noInlineConfig, resultVersion);
+      ruleSet, content, config, frontMatter, noInlineConfig, resultVersion);
     callback(null, result);
   }
   // Make a/synchronous call to read file
@@ -338,6 +346,7 @@ function lintInput(options, synchronous, callback) {
   // Normalize inputs
   options = options || {};
   callback = callback || function noop() {};
+  var ruleSet = rules.concat(options.customRules || []);
   var files = [];
   if (Array.isArray(options.files)) {
     files = options.files.slice();
@@ -351,12 +360,13 @@ function lintInput(options, synchronous, callback) {
   var noInlineConfig = !!options.noInlineConfig;
   var resultVersion = (options.resultVersion === undefined) ?
     2 : options.resultVersion;
-  var results = new Results();
+  var results = newResults(ruleSet);
   // Helper to lint the next file in the array
   function lintFilesArray() {
     var file = files.shift();
     if (file) {
       lintFile(
+        ruleSet,
         file,
         config,
         frontMatter,
@@ -378,6 +388,7 @@ function lintInput(options, synchronous, callback) {
   // Lint strings
   Object.keys(strings).forEach(function forKey(key) {
     var result = lintContent(
+      ruleSet,
       strings[key] || "",
       config,
       frontMatter,

test/custom-rules.md

@@ -0,0 +1,12 @@
+# Heading
+
+Sample text.
+<!-- markdownlint-disable letters-e-x -->
+Sample text.
+<!-- markdownlint-enable LETTERS-E-X -->
+Sample text.
+<!-- markdownlint-disable TeSt -->
+Sample text.
+<!-- markdownlint-enable TEST -->
+
+> Blockquote

test/markdownlint-test.js

@@ -8,6 +8,7 @@ var tv4 = require("tv4");
 var markdownlint = require("../lib/markdownlint");
 var shared = require("../lib/shared");
 var rules = require("../lib/rules");
+var customRules = require("./rules");
 var defaultConfig = require("./markdownlint-test-default-config.json");
 var configSchema = require("../schema/markdownlint-config-schema.json");
 
@@ -890,6 +891,7 @@ module.exports.readmeHeaders = function readmeHeaders(test) {
           "## API",
           "### Linting",
           "#### options",
+          "##### options.customRules",
           "##### options.files",
           "##### options.strings",
           "##### options.config",
@@ -1546,3 +1548,278 @@ module.exports.configBadChildJsonSync = function configBadChildJsonSync(test) {
   }, "Did not get exception for bad child JSON.");
   test.done();
 };
+
+module.exports.customRulesV0 = function customRulesV0(test) {
+  test.expect(4);
+  var customRulesMd = "./test/custom-rules.md";
+  var options = {
+    "customRules": customRules.all,
+    "files": [ customRulesMd ],
+    "resultVersion": 0
+  };
+  markdownlint(options, function callback(err, actualResult) {
+    test.ifError(err);
+    var expectedResult = {};
+    expectedResult[customRulesMd] = {
+      "blockquote": [ 12 ],
+      "every-n-lines": [ 2, 4, 6, 10, 12 ],
+      "letters-E-X": [ 3, 7 ]
+    };
+    test.deepEqual(actualResult, expectedResult, "Undetected issues.");
+    var actualMessage = actualResult.toString();
+    var expectedMessage =
+      "./test/custom-rules.md: 12: blockquote" +
+      " Rule that reports an error for blockquotes\n" +
+      "./test/custom-rules.md: 2: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 4: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 6: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 10: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 12: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 3: letters-E-X" +
+      " Rule that reports an error for lines with the letters 'EX'\n" +
+      "./test/custom-rules.md: 7: letters-E-X" +
+      " Rule that reports an error for lines with the letters 'EX'";
+    test.equal(actualMessage, expectedMessage, "Incorrect message (name).");
+    actualMessage = actualResult.toString(true);
+    expectedMessage =
+      "./test/custom-rules.md: 12: blockquote" +
+      " Rule that reports an error for blockquotes\n" +
+      "./test/custom-rules.md: 2: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 4: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 6: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 10: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 12: every-n-lines" +
+      " Rule that reports an error every N lines\n" +
+      "./test/custom-rules.md: 3: letter-E-letter-X" +
+      " Rule that reports an error for lines with the letters 'EX'\n" +
+      "./test/custom-rules.md: 7: letter-E-letter-X" +
+      " Rule that reports an error for lines with the letters 'EX'";
+    test.equal(actualMessage, expectedMessage, "Incorrect message (alias).");
+    test.done();
+  });
+};
+
+module.exports.customRulesV1 = function customRulesV1(test) {
+  test.expect(3);
+  var customRulesMd = "./test/custom-rules.md";
+  var options = {
+    "customRules": customRules.all,
+    "files": [ customRulesMd ],
+    "resultVersion": 1
+  };
+  markdownlint(options, function callback(err, actualResult) {
+    test.ifError(err);
+    var expectedResult = {};
+    expectedResult[customRulesMd] = [
+      { "lineNumber": 12,
+        "ruleName": "blockquote",
+        "ruleAlias": "blockquote",
+        "ruleDescription": "Rule that reports an error for blockquotes",
+        "errorDetail": "Blockquote spans 1 line(s).",
+        "errorContext": "> Block",
+        "errorRange": null },
+      { "lineNumber": 2,
+        "ruleName": "every-n-lines",
+        "ruleAlias": "every-n-lines",
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 2",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 4,
+        "ruleName": "every-n-lines",
+        "ruleAlias": "every-n-lines",
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 4",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 6,
+        "ruleName": "every-n-lines",
+        "ruleAlias": "every-n-lines",
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 6",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 10,
+        "ruleName": "every-n-lines",
+        "ruleAlias": "every-n-lines",
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 10",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 12,
+        "ruleName": "every-n-lines",
+        "ruleAlias": "every-n-lines",
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 12",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 3,
+        "ruleName": "letters-E-X",
+        "ruleAlias": "letter-E-letter-X",
+        "ruleDescription":
+          "Rule that reports an error for lines with the letters 'EX'",
+        "errorDetail": null,
+        "errorContext": "text",
+        "errorRange": null },
+      { "lineNumber": 7,
+        "ruleName": "letters-E-X",
+        "ruleAlias": "letter-E-letter-X",
+        "ruleDescription":
+          "Rule that reports an error for lines with the letters 'EX'",
+        "errorDetail": null,
+        "errorContext": "text",
+        "errorRange": null }
+    ];
+    test.deepEqual(actualResult, expectedResult, "Undetected issues.");
+    var actualMessage = actualResult.toString();
+    var expectedMessage =
+      "./test/custom-rules.md: 12: blockquote/blockquote" +
+      " Rule that reports an error for blockquotes" +
+      " [Blockquote spans 1 line(s).] [Context: \"> Block\"]\n" +
+      "./test/custom-rules.md: 2: every-n-lines/every-n-lines" +
+      " Rule that reports an error every N lines [Line number 2]\n" +
+      "./test/custom-rules.md: 4: every-n-lines/every-n-lines" +
+      " Rule that reports an error every N lines [Line number 4]\n" +
+      "./test/custom-rules.md: 6: every-n-lines/every-n-lines" +
+      " Rule that reports an error every N lines [Line number 6]\n" +
+      "./test/custom-rules.md: 10: every-n-lines/every-n-lines" +
+      " Rule that reports an error every N lines [Line number 10]\n" +
+      "./test/custom-rules.md: 12: every-n-lines/every-n-lines" +
+      " Rule that reports an error every N lines [Line number 12]\n" +
+      "./test/custom-rules.md: 3: letters-E-X/letter-E-letter-X" +
+      " Rule that reports an error for lines with the letters 'EX'" +
+      " [Context: \"text\"]\n" +
+      "./test/custom-rules.md: 7: letters-E-X/letter-E-letter-X" +
+      " Rule that reports an error for lines with the letters 'EX'" +
+      " [Context: \"text\"]";
+    test.equal(actualMessage, expectedMessage, "Incorrect message.");
+    test.done();
+  });
+};
+
+module.exports.customRulesV2 = function customRulesV2(test) {
+  test.expect(3);
+  var customRulesMd = "./test/custom-rules.md";
+  var options = {
+    "customRules": customRules.all,
+    "files": [ customRulesMd ],
+    "resultVersion": 2
+  };
+  markdownlint(options, function callback(err, actualResult) {
+    test.ifError(err);
+    var expectedResult = {};
+    expectedResult[customRulesMd] = [
+      { "lineNumber": 12,
+        "ruleNames": [ "blockquote" ],
+        "ruleDescription": "Rule that reports an error for blockquotes",
+        "errorDetail": "Blockquote spans 1 line(s).",
+        "errorContext": "> Block",
+        "errorRange": null },
+      { "lineNumber": 2,
+        "ruleNames": [ "every-n-lines" ],
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 2",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 4,
+        "ruleNames": [ "every-n-lines" ],
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 4",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 6,
+        "ruleNames": [ "every-n-lines" ],
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 6",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 10,
+        "ruleNames": [ "every-n-lines" ],
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 10",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 12,
+        "ruleNames": [ "every-n-lines" ],
+        "ruleDescription": "Rule that reports an error every N lines",
+        "errorDetail": "Line number 12",
+        "errorContext": null,
+        "errorRange": null },
+      { "lineNumber": 3,
+        "ruleNames": [ "letters-E-X", "letter-E-letter-X", "contains-ex" ],
+        "ruleDescription":
+          "Rule that reports an error for lines with the letters 'EX'",
+        "errorDetail": null,
+        "errorContext": "text",
+        "errorRange": null },
+      { "lineNumber": 7,
+        "ruleNames": [ "letters-E-X", "letter-E-letter-X", "contains-ex" ],
+        "ruleDescription":
+          "Rule that reports an error for lines with the letters 'EX'",
+        "errorDetail": null,
+        "errorContext": "text",
+        "errorRange": null }
+    ];
+    test.deepEqual(actualResult, expectedResult, "Undetected issues.");
+    var actualMessage = actualResult.toString();
+    var expectedMessage =
+      "./test/custom-rules.md: 12: blockquote" +
+      " Rule that reports an error for blockquotes" +
+      " [Blockquote spans 1 line(s).] [Context: \"> Block\"]\n" +
+      "./test/custom-rules.md: 2: every-n-lines" +
+      " Rule that reports an error every N lines [Line number 2]\n" +
+      "./test/custom-rules.md: 4: every-n-lines" +
+      " Rule that reports an error every N lines [Line number 4]\n" +
+      "./test/custom-rules.md: 6: every-n-lines" +
+      " Rule that reports an error every N lines [Line number 6]\n" +
+      "./test/custom-rules.md: 10: every-n-lines" +
+      " Rule that reports an error every N lines [Line number 10]\n" +
+      "./test/custom-rules.md: 12: every-n-lines" +
+      " Rule that reports an error every N lines [Line number 12]\n" +
+      "./test/custom-rules.md: 3: letters-E-X/letter-E-letter-X/contains-ex" +
+      " Rule that reports an error for lines with the letters 'EX'" +
+      " [Context: \"text\"]\n" +
+      "./test/custom-rules.md: 7: letters-E-X/letter-E-letter-X/contains-ex" +
+      " Rule that reports an error for lines with the letters 'EX'" +
+      " [Context: \"text\"]";
+    test.equal(actualMessage, expectedMessage, "Incorrect message.");
+    test.done();
+  });
+};
+
+module.exports.customRulesConfig = function customRulesConfig(test) {
+  test.expect(2);
+  var customRulesMd = "./test/custom-rules.md";
+  var options = {
+    "customRules": customRules.all,
+    "files": [ customRulesMd ],
+    "config": {
+      "blockquote": true,
+      "every-n-lines": {
+        "n": 3
+      },
+      "letters-e-x": false
+    },
+    "resultVersion": 0
+  };
+  markdownlint(options, function callback(err, actualResult) {
+    test.ifError(err);
+    var expectedResult = {};
+    expectedResult[customRulesMd] = {
+      "blockquote": [ 12 ],
+      "every-n-lines": [ 3, 6, 12 ],
+      "letters-E-X": [ 7 ]
+    };
+    test.deepEqual(actualResult, expectedResult, "Undetected issues.");
+    test.done();
+  });
+};

test/rules/blockquote.js

@@ -0,0 +1,22 @@
+// @ts-check
+
+"use strict";
+
+module.exports = {
+  "names": [ "blockquote" ],
+  "description": "Rule that reports an error for blockquotes",
+  "tags": [ "test" ],
+  "function": function rule(params, onError) {
+    params.tokens.filter(function filterToken(token) {
+      return token.type === "blockquote_open";
+    }).forEach(function forToken(blockquote) {
+      var lines = blockquote.map[1] - blockquote.map[0];
+      onError({
+        "lineNumber": blockquote.lineNumber,
+        "detail": "Blockquote spans " + lines + " line(s).",
+        "context": blockquote.line.substr(0, 7),
+        "range": null
+      });
+    });
+  }
+};

test/rules/every-n-lines.js

@@ -0,0 +1,23 @@
+// @ts-check
+
+"use strict";
+
+module.exports = {
+  "names": [ "every-n-lines" ],
+  "description": "Rule that reports an error every N lines",
+  "tags": [ "test" ],
+  "function": function rule(params, onError) {
+    var n = params.config.n || 2;
+    params.lines.forEach(function forLine(line, lineIndex) {
+      var lineNumber = lineIndex + 1;
+      if ((lineNumber % n) === 0) {
+        onError({
+          "lineNumber": lineNumber,
+          "detail": "Line number " + lineNumber,
+          "context": null,
+          "range": null
+        });
+      }
+    });
+  }
+};

test/rules/letters-E-X.js

@@ -0,0 +1,28 @@
+// @ts-check
+
+"use strict";
+
+module.exports = {
+  "names": [ "letters-E-X", "letter-E-letter-X", "contains-ex" ],
+  "description": "Rule that reports an error for lines with the letters 'EX'",
+  "tags": [ "test" ],
+  "function": function rule(params, onError) {
+    params.tokens.filter(function filterToken(token) {
+      return token.type === "inline";
+    }).forEach(function forToken(inline) {
+      inline.children.filter(function filterChild(child) {
+        return child.type === "text";
+      }).forEach(function forChild(text) {
+        var index = text.content.toLowerCase().indexOf("ex");
+        if (index !== -1) {
+          onError({
+            "lineNumber": text.lineNumber,
+            "detail": null,
+            "context": text.content.substr(index - 1, 4),
+            "range": null
+          });
+        }
+      });
+    });
+  }
+};

test/rules/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "markdownlint-rules-test",
+  "version": "0.0.1",
+  "description": "Package of markdownlint custom rules used for testing",
+  "main": "rules.js",
+  "author": "David Anson (https://dlaa.me/)",
+  "homepage": "https://github.com/DavidAnson/markdownlint",
+  "license": "MIT",
+  "keywords": [
+    "markdownlint-rules"
+  ],
+  "private": true
+}

test/rules/rules.js

@@ -0,0 +1,18 @@
+// @ts-check
+
+"use strict";
+
+var blockquote = require("./blockquote");
+module.exports.blockquote = blockquote;
+
+var everyNLines = require("./every-n-lines");
+module.exports.everyNLines = everyNLines;
+
+var lettersEX = require("./letters-E-X");
+module.exports.lettersEX = lettersEX;
+
+module.exports.all = [
+  blockquote,
+  everyNLines,
+  lettersEX
+];