Add MD047/single-trailing-newline for enforcing new lines at the end of file (fixes #89).

README.md

@@ -88,6 +88,7 @@ playground for learning and exploring.
 * **[MD044](doc/Rules.md#md044)** *proper-names* - Proper names should have the correct capitalization
 * **[MD045](doc/Rules.md#md045)** *no-alt-text* - Images should have alternate text (alt text)
 * **[MD046](doc/Rules.md#md046)** *code-block-style* - Code block style
+* **[MD047](doc/Rules.md#md047)** *single-trailing-newline* - Files should end with a single newline character
 
 See [Rules.md](doc/Rules.md) for more details.
 
@@ -102,7 +103,7 @@ Tags group related rules and can be used to enable/disable multiple rules at onc
 * **accessibility** - MD045
 * **atx** - MD018, MD019
 * **atx_closed** - MD020, MD021
-* **blank_lines** - MD012, MD022, MD031, MD032
+* **blank_lines** - MD012, MD022, MD031, MD032, MD047
 * **blockquote** - MD027, MD028
 * **bullet** - MD004, MD005, MD006, MD007, MD032
 * **code** - MD014, MD031, MD038, MD040, MD046

doc/Rules.md

@@ -1576,3 +1576,30 @@ To fix violations of this rule, use a consistent style (either indenting or code
 
 The specified style can be specific (`fenced`, `indented`) or simply require that usage
 be consistent within the document (`consistent`).
+
+<a name="md047"></a>
+
+## MD047 - Files should end with a single newline character
+
+Tags: blank_lines
+
+Aliases: single-trailing-newline
+
+This rule is triggered when there is not a single newline character at the end of a file.
+
+Example that triggers the rule:
+
+```markdown
+# Heading
+
+This file ends without a newline.[EOF]
+```
+
+To fix the violation, add a newline character to the end of the file:
+
+```markdown
+# Heading
+
+This file ends with a newline.
+[EOF]
+```

lib/md047.js

@@ -0,0 +1,18 @@
+// @ts-check
+
+"use strict";
+
+const { addError, isBlankLine } = require("../helpers");
+
+module.exports = {
+  "names": [ "MD047", "single-trailing-newline" ],
+  "description": "Files should end with a single newline character",
+  "tags": [ "blank_lines" ],
+  "function": function MD047(params, onError) {
+    const lastLineNumber = params.lines.length;
+    const lastLine = params.lines[lastLineNumber - 1];
+    if (!isBlankLine(lastLine)) {
+      addError(onError, lastLineNumber);
+    }
+  }
+};

lib/rules.js

@@ -49,7 +49,8 @@ const rules = [
   require("./md043"),
   require("./md044"),
   require("./md045"),
-  require("./md046")
+  require("./md046"),
+  require("./md047")
 ];
 rules.forEach((rule) => {
   const name = rule.names[0].toLowerCase();

schema/markdownlint-config-schema.json

@@ -1297,6 +1297,16 @@
       },
       "additionalProperties": false
     },
+    "MD047": {
+      "description": "MD047/single-trailing-newline - Files should end with a single newline character",
+      "type": "boolean",
+      "default": true
+    },
+    "single-trailing-newline": {
+      "description": "MD047/single-trailing-newline - Files should end with a single newline character",
+      "type": "boolean",
+      "default": true
+    },
     "headings": {
       "description": "headings - MD001, MD002, MD003, MD018, MD019, MD020, MD021, MD022, MD023, MD024, MD025, MD026, MD036, MD041, MD043",
       "type": "boolean",
@@ -1338,7 +1348,7 @@
       "default": true
     },
     "blank_lines": {
-      "description": "blank_lines - MD012, MD022, MD031, MD032",
+      "description": "blank_lines - MD012, MD022, MD031, MD032, MD047",
       "type": "boolean",
       "default": true
     },

test/break-all-the-rules.md

@@ -78,4 +78,4 @@ code fence without language {MD040:73} {MD046:73}
 
 markdownLint {MD044}
 
-![](image.jpg) {MD045}
+![](image.jpg) {MD045} {MD047}

test/detailed-results-MD041-MD050.md

@@ -23,3 +23,5 @@ Fenced code
 ```
 
     Indented code
+
+Missing newline character

test/detailed-results-MD041-MD050.results.json

@@ -45,7 +45,7 @@
         "errorRange": [25, 13]
     },
     {
-        "lineNumber": 26,
+        "lineNumber": 27,
         "ruleNames": [ "MD043", "required-headings", "required-headers" ],
         "ruleDescription": "Required heading structure",
         "ruleInformation": "https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/Rules.md#md043",
@@ -97,5 +97,14 @@
         "errorDetail": "Expected: fenced; Actual: indented",
         "errorContext": null,
         "errorRange": null
+    },
+    {
+        "lineNumber": 27,
+        "ruleNames": [ "MD047", "single-trailing-newline" ],
+        "ruleDescription": "Files should end with a single newline character",
+        "ruleInformation": "https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/Rules.md#md047",
+        "errorDetail": null,
+        "errorContext": null,
+        "errorRange": null
     }
 ]

test/fenced_code_without_blank_lines.md

@@ -38,5 +38,5 @@ code
 text
 
 ```
-code at end of file without newline
+code at end of file without newline {MD047:42}
 ```

test/lists_without_blank_lines.md

@@ -72,4 +72,4 @@ code
 
 text
 
-* list (on last line without newline)
+* list (on last line without newline) {MD047}

test/markdownlint-test.js

@@ -250,7 +250,7 @@ module.exports.resultFormattingV1 = function resultFormattingV1(test) {
   const options = {
     "strings": {
       "truncate":
-        "#  Multiple spaces inside hashes on closed atx style heading  #"
+        "#  Multiple spaces inside hashes on closed atx style heading  #\n"
     },
     "files": [
       "./test/atx_heading_spacing.md",
@@ -352,7 +352,7 @@ module.exports.resultFormattingV2 = function resultFormattingV2(test) {
   const options = {
     "strings": {
       "truncate":
-        "#  Multiple spaces inside hashes on closed atx style heading  #"
+        "#  Multiple spaces inside hashes on closed atx style heading  #\n"
     },
     "files": [
       "./test/atx_heading_spacing.md",
@@ -448,14 +448,14 @@ module.exports.stringInputLineEndings = function stringInputLineEndings(test) {
   test.expect(2);
   const options = {
     "strings": {
-      "cr": "One\rTwo\r#Three",
-      "lf": "One\nTwo\n#Three",
-      "crlf": "One\r\nTwo\r\n#Three",
-      "mixed": "One\rTwo\n#Three",
-      "crnel": "One\r\u0085Two\r\u0085#Three",
-      "snl": "One\u2424Two\u2424#Three",
-      "lsep": "One\u2028Two\u2028#Three",
-      "nel": "One\u0085Two\u0085#Three"
+      "cr": "One\rTwo\r#Three\n",
+      "lf": "One\nTwo\n#Three\n",
+      "crlf": "One\r\nTwo\r\n#Three\n",
+      "mixed": "One\rTwo\n#Three\n",
+      "crnel": "One\r\u0085Two\r\u0085#Three\n",
+      "snl": "One\u2424Two\u2424#Three\n",
+      "lsep": "One\u2028Two\u2028#Three\n",
+      "nel": "One\u0085Two\u0085#Three\n"
     },
     "config": defaultConfig,
     "resultVersion": 0
@@ -811,7 +811,8 @@ module.exports.styleAll = function styleAll(test) {
         "MD041": [ 1 ],
         "MD042": [ 77 ],
         "MD045": [ 81 ],
-        "MD046": [ 49, 73 ]
+        "MD046": [ 49, 73 ],
+        "MD047": [ 81 ]
       }
     };
     test.deepEqual(actualResult, expectedResult, "Undetected issues.");
@@ -851,7 +852,8 @@ module.exports.styleRelaxed = function styleRelaxed(test) {
         "MD036": [ 65 ],
         "MD042": [ 77 ],
         "MD045": [ 81 ],
-        "MD046": [ 49, 73 ]
+        "MD046": [ 49, 73 ],
+        "MD047": [ 81 ]
       }
     };
     test.deepEqual(actualResult, expectedResult, "Undetected issues.");
@@ -917,7 +919,7 @@ module.exports.noInlineConfig = function noInlineConfig(test) {
         "",
         "<!-- markdownlint-enable-->",
         "",
-        "\tTab"
+        "\tTab\n"
       ].join("\n")
     },
     "noInlineConfig": true,
@@ -1093,7 +1095,7 @@ module.exports.missingStringValue = function missingStringValue(test) {
 };
 
 module.exports.readme = function readme(test) {
-  test.expect(111);
+  test.expect(113);
   const tagToRules = {};
   rules.forEach(function forRule(rule) {
     rule.tags.forEach(function forTag(tag) {
@@ -1159,7 +1161,7 @@ module.exports.readme = function readme(test) {
 };
 
 module.exports.doc = function doc(test) {
-  test.expect(320);
+  test.expect(327);
   fs.readFile("doc/Rules.md", helpers.utf8Encoding,
     function readFile(err, contents) {
       test.ifError(err);
@@ -1859,7 +1861,7 @@ module.exports.configBadHybridSync = function configBadHybridSync(test) {
 
 module.exports.allBuiltInRulesHaveValidUrl =
   function allBuiltInRulesHaveValidUrl(test) {
-    test.expect(126);
+    test.expect(129);
     rules.forEach(function forRule(rule) {
       test.ok(rule.information);
       test.ok(Object.getPrototypeOf(rule.information) === URL.prototype);
@@ -2216,7 +2218,7 @@ module.exports.customRulesNpmPackage = function customRulesNpmPackage(test) {
   const options = {
     "customRules": [ require("./rules/npm") ],
     "strings": {
-      "string": "# Text\n\n---\n\nText"
+      "string": "# Text\n\n---\n\nText\n"
     },
     "resultVersion": 0
   };
@@ -2515,7 +2517,7 @@ module.exports.customRulesOnErrorLazy = function customRulesOnErrorLazy(test) {
       }
     ],
     "strings": {
-      "string": "# Heading"
+      "string": "# Heading\n"
     }
   };
   markdownlint(options, function callback(err, actualResult) {
@@ -2602,7 +2604,7 @@ module.exports.markdownItPluginsSingle =
     test.expect(2);
     markdownlint({
       "strings": {
-        "string": "# Heading\n\nText [ link ](https://example.com)"
+        "string": "# Heading\n\nText [ link ](https://example.com)\n"
       },
       "markdownItPlugins": [
         [
@@ -2627,7 +2629,7 @@ module.exports.markdownItPluginsMultiple =
     test.expect(4);
     markdownlint({
       "strings": {
-        "string": "# Heading\n\nText H~2~0 text 29^th^ text"
+        "string": "# Heading\n\nText H~2~0 text 29^th^ text\n"
       },
       "markdownItPlugins": [
         [ pluginSub ],
@@ -2680,7 +2682,7 @@ $$
 1
 $$$$
 2
-$$`
+$$\n`
       },
       "markdownItPlugins": [ [ pluginKatex ] ],
       "resultVersion": 0

test/md022-line-number-out-of-range.json

@@ -0,0 +1,4 @@
+{
+  "default": true,
+  "MD047": false
+}

test/required-headings-missing-last.md

@@ -4,4 +4,4 @@ One
 Two
 ---
 
-{MD043}
+{MD043} {MD047}