David Sveningsson · David Sveningsson · David Sveningsson · David Sveningsson · David Sveningsson · WhiteSource Renovate
65 changed files
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
 image: node:latest

 include:
-  - template: Security/License-Management.gitlab-ci.yml
+  - template: License-Scanning.gitlab-ci.yml

 stages:
  - prepare
@@ -120,6 +120,7 @@ Node 13.x (current):

 Release:
  stage: release
+  image: node:12
  only:
    - web
  variables:
@@ -128,7 +129,7 @@ Release:
    GIT_COMMITTER_NAME: "David Sveningsson"
    GIT_COMMITTER_EMAIL: "ext@sidvind.com"
  script:
-    - npm run semantic-release
+    - npm run semantic-release -- --debug

 .downstream: &downstream
  stage: postrelease

--- a/CHANGELOG.md
+++ b/CHANGELOG.md
 # html-validate changelog

+# [2.18.0](https://gitlab.com/html-validate/html-validate/compare/v2.17.1...v2.18.0) (2020-03-11)
+
+### Bug Fixes
+
+- validate `input[list]` ([9c70db2](https://gitlab.com/html-validate/html-validate/commit/9c70db243aa3fa0c9243bc6fd6a206bac28a5873))
+- **rules:** `no-dup-id` handles when id is set but omitted value ([5f678a5](https://gitlab.com/html-validate/html-validate/commit/5f678a566c006d50b90fee23d140b5f49784b0e0))
+- **rules:** `no-missing-references` ignores omitted references ([b8863cd](https://gitlab.com/html-validate/html-validate/commit/b8863cd8ebd8c5c05e97ef9e5e662f406aa1cb92))
+- **rules:** add contextual documentation for `deprecated` ([7fbf433](https://gitlab.com/html-validate/html-validate/commit/7fbf433f9ce70ce34759448936d40c7dd96f55ae))
+- **rules:** add contextual documentation for `element-name` ([2a98bad](https://gitlab.com/html-validate/html-validate/commit/2a98bada16a15c802a3e050e9274153237e916fd))
+- **rules:** better and more contextual messages for `deprecated` ([3602be7](https://gitlab.com/html-validate/html-validate/commit/3602be730dd2ec54e1de702171ce606e4043c02a))
+- **rules:** contextual documentation for `deprecated-rule` ([8b10601](https://gitlab.com/html-validate/html-validate/commit/8b10601405f74ddbe62a6d666153dece1b3ad9a4))
+- **rules:** improve documentation for `doctype-html` ([1a896a8](https://gitlab.com/html-validate/html-validate/commit/1a896a87f8e7c253e4d21faf01aae6f52df754f8))
+- **shim:** expose `ConfigError` and `UserError` ([2d002c7](https://gitlab.com/html-validate/html-validate/commit/2d002c79f1f6f088c1792de768ba80777629b739))
+- **transform:** ignore non-string values in `TemplateExtractor` ([7f27c8b](https://gitlab.com/html-validate/html-validate/commit/7f27c8b6b0ff4f4afd85501b0b554886742b5c6f))
+- allow both null and empty string when attribute allows empty values ([5b6991b](https://gitlab.com/html-validate/html-validate/commit/5b6991b6ea7d8b4418168b1f9d0f8bef7cac935e))
+
+### Features
+
+- `attribute-allowed-values` handle omitted values ([962d079](https://gitlab.com/html-validate/html-validate/commit/962d0791dae6ad4fed663909556c480f5789cd81))
+- new rule `attribute-empty-style` ([a328b55](https://gitlab.com/html-validate/html-validate/commit/a328b558adced37c05b76dddd6cf6f83d36fe72d))
+
 ## [2.17.1](https://gitlab.com/html-validate/html-validate/compare/v2.17.0...v2.17.1) (2020-03-02)

 ### Bug Fixes

--- a/docs/__tests__/__snapshots__/index.md.spec.ts.snap
+++ b/docs/__tests__/__snapshots__/index.md.spec.ts.snap
@@ -74,7 +74,9 @@ Array [
      },
      Object {
        "column": 4,
-        "context": undefined,
+        "context": Object {
+          "tagName": "my-deprecated",
+        },
        "line": 3,
        "message": "<my-deprecated> is deprecated: replaced with <my-other>",
        "offset": 39,
@@ -123,7 +125,11 @@ Array [
      },
      Object {
        "column": 6,
-        "context": undefined,
+        "context": Object {
+          "documentation": "\`<blink>\` has no direct replacement and blinking text is frowned upon by accessibility standards.",
+          "source": "non-standard",
+          "tagName": "blink",
+        },
        "line": 8,
        "message": "<blink> is deprecated",
        "offset": 138,

--- a/docs/rules/__tests__/__snapshots__/attribute-allowed-values.md.spec.ts.snap
+++ b/docs/rules/__tests__/__snapshots__/attribute-allowed-values.md.spec.ts.snap
@@ -5,9 +5,27 @@ exports[`docs/rules/attribute-allowed-values.md inline validation: correct 1`] =
 exports[`docs/rules/attribute-allowed-values.md inline validation: incorrect 1`] = `
 Array [
  Object {
-    "errorCount": 1,
+    "errorCount": 2,
    "filePath": "inline",
    "messages": Array [
+      Object {
+        "column": 4,
+        "context": Object {
+          "allowed": Array [
+            /\\.\\*/,
+          ],
+          "attribute": "href",
+          "element": "a",
+          "value": "",
+        },
+        "line": 1,
+        "message": "Attribute \\"href\\" is missing value",
+        "offset": 3,
+        "ruleId": "attribute-allowed-values",
+        "selector": "a",
+        "severity": 2,
+        "size": 4,
+      },
      Object {
        "column": 14,
        "context": Object {
@@ -39,16 +57,17 @@ Array [
          "element": "input",
          "value": "foobar",
        },
-        "line": 1,
+        "line": 2,
        "message": "Attribute \\"type\\" has invalid value \\"foobar\\"",
-        "offset": 13,
+        "offset": 29,
        "ruleId": "attribute-allowed-values",
        "selector": "input",
        "severity": 2,
        "size": 6,
      },
    ],
-    "source": "<input type=\\"foobar\\">",
+    "source": "<a href>...</a>
+<input type=\\"foobar\\">",
    "warningCount": 0,
  },
 ]

--- a/docs/rules/__tests__/__snapshots__/attribute-empty-style.md.spec.ts.snap
+++ b/docs/rules/__tests__/__snapshots__/attribute-empty-style.md.spec.ts.snap
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`docs/rules/attribute-empty-style.md inline validation: correct 1`] = `Array []`;
+
+exports[`docs/rules/attribute-empty-style.md inline validation: incorrect 1`] = `
+Array [
+  Object {
+    "errorCount": 1,
+    "filePath": "inline",
+    "messages": Array [
+      Object {
+        "column": 4,
+        "context": undefined,
+        "line": 1,
+        "message": "Attribute \\"download\\" should omit value",
+        "offset": 3,
+        "ruleId": "attribute-empty-style",
+        "selector": "a",
+        "severity": 2,
+        "size": 8,
+      },
+    ],
+    "source": "<a download=\\"\\"></a>",
+    "warningCount": 0,
+  },
+]
+`;
--- a/docs/rules/__tests__/__snapshots__/deprecated.md.spec.ts.snap
+++ b/docs/rules/__tests__/__snapshots__/deprecated.md.spec.ts.snap
@@ -10,7 +10,9 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "tagName": "my-element",
+        },
        "line": 1,
        "message": "<my-element> is deprecated: replaced with <other-element>",
        "offset": 1,
@@ -34,9 +36,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use the CSS \`text-align\` or \`margin: auto\` properties instead.",
+          "message": "use CSS instead",
+          "source": "html4",
+          "tagName": "center",
+        },
        "line": 1,
-        "message": "<center> is deprecated",
+        "message": "<center> is deprecated: use CSS instead",
        "offset": 1,
        "ruleId": "deprecated",
        "selector": "center",
@@ -45,9 +52,14 @@ Array [
      },
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use CSS \`font-size\` property instead.",
+          "message": "use CSS instead",
+          "source": "html5",
+          "tagName": "big",
+        },
        "line": 2,
-        "message": "<big> is deprecated",
+        "message": "<big> is deprecated: use CSS instead",
        "offset": 22,
        "ruleId": "deprecated",
        "selector": "big",

--- a/docs/rules/__tests__/__snapshots__/element-name.md.spec.ts.snap
+++ b/docs/rules/__tests__/__snapshots__/element-name.md.spec.ts.snap
@@ -10,7 +10,11 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "blacklist": Array [],
+          "pattern": "^[a-z][a-z0-9\\\\-._]*-[a-z0-9\\\\-._]*$",
+          "tagName": "foobar",
+        },
        "line": 1,
        "message": "<foobar> is not a valid element name",
        "offset": 1,

--- a/docs/rules/__tests__/attribute-allowed-values.md.spec.ts
+++ b/docs/rules/__tests__/attribute-allowed-values.md.spec.ts
 import HtmlValidate from "../../../src/htmlvalidate";

 const markup: { [key: string]: string } = {};
-markup["incorrect"] = `<input type="foobar">`;
-markup["correct"] = `<input type="text">`;
+markup["incorrect"] = `<a href>...</a>
+<input type="foobar">`;
+markup["correct"] = `<a href="page.html">...</a>
+<input type="text">`;

 describe("docs/rules/attribute-allowed-values.md", () => {
 	it("inline validation: incorrect", () => {

--- a/docs/rules/__tests__/attribute-empty-style.md.spec.ts
+++ b/docs/rules/__tests__/attribute-empty-style.md.spec.ts
+import HtmlValidate from "../../../src/htmlvalidate";
+
+const markup: { [key: string]: string } = {};
+markup["incorrect"] = `<a download=""></a>`;
+markup["correct"] = `<a download></a>`;
+
+describe("docs/rules/attribute-empty-style.md", () => {
+	it("inline validation: incorrect", () => {
+		const htmlvalidate = new HtmlValidate({"rules":{"attribute-empty-style":"error"}});
+		const report = htmlvalidate.validateString(markup["incorrect"]);
+		expect(report.results).toMatchSnapshot();
+	});
+	it("inline validation: correct", () => {
+		const htmlvalidate = new HtmlValidate({"rules":{"attribute-empty-style":"error"}});
+		const report = htmlvalidate.validateString(markup["correct"]);
+		expect(report.results).toMatchSnapshot();
+	});
+});
--- a/docs/rules/attribute-allowed-values.md
+++ b/docs/rules/attribute-allowed-values.md
@@ -28,11 +28,13 @@ The requirements comes from the [element metadata](/usage/elements.html):
 Examples of **incorrect** code for this rule:

 <validate name="incorrect" rules="attribute-allowed-values">
+    <a href>...</a>
    <input type="foobar">
 </validate>

 Examples of **correct** code for this rule:

 <validate name="correct" rules="attribute-allowed-values">
+    <a href="page.html">...</a>
    <input type="text">
 </validate>
--- a/docs/rules/attribute-boolean-style.md
+++ b/docs/rules/attribute-boolean-style.md
@@ -7,7 +7,19 @@ summary: Require a specific style for boolean attributes

 # Boolean attribute style (`attribute-boolean-style`)

-Require a specific style when writing boolean attributes.
+Boolean attributes are attributes without a value and the presence of the attribute is considered a boolean `true` and absense a boolean `false`.
+The [HTML5 standard][whatwg] allows three styles to write boolean attributes:
+
+- `<input required>` (omitting the value)
+- `<input required="">` (empty string)
+- `<input required="required">` (attribute name)
+
+This rule requires a specific style when writing boolean attributes.
+Default is to omit the value.
+
+This rule does not have an effect on regular attributes with empty values, see {@link attribute-empty-style} instead.
+
+[whatwg]: https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#boolean-attributes

 ## Rule details


--- a/docs/rules/attribute-empty-style.md
+++ b/docs/rules/attribute-empty-style.md
+---
+docType: rule
+name: attribute-empty-style
+category: style
+summary: Require a specific style for empty attributes
+---
+
+# Empty attribute style (`attribute-empty-style`)
+
+Attributes without a value is implied to be an empty string by the [HTML5 standard][whatwg], e.g. `<a download>` and `<a download="">` are equal.
+This rule requires a specific style when writing empty attributes.
+Default is to omit the empty string `""`.
+
+This rule does not have an effect on boolean attributes, see {@link attribute-boolean-style} instead.
+
+[whatwg]: https://html.spec.whatwg.org/multipage/syntax.html#attributes-2
+
+## Rule details
+
+Examples of **incorrect** code for this rule:
+
+<validate name="incorrect" rules="attribute-empty-style">
+    <a download=""></a>
+</validate>
+
+Examples of **correct** code for this rule:
+
+<validate name="correct" rules="attribute-empty-style">
+    <a download></a>
+</validate>
+
+## Options
+
+This rule takes an optional object:
+
+```javascript
+{
+	"style": "omit"
+}
+```
+
+### Style
+
+- `omit` require empty attributes to omit value, e.g. `<a download></a>`
+- `empty` require empty attributes to be empty string, e.g. `<a download=""></a>`
--- a/docs/rules/no-missing-references.md
+++ b/docs/rules/no-missing-references.md
@@ -5,17 +5,18 @@ category: document
 summary: Require all element references to exist
 ---

-# no missing references (`no-missing-references`)
+# No missing references (`no-missing-references`)

 Require all elements referenced by attributes such as `for` to exist in the
 current document.

 Checked attributes:

- `for`
- `aria-controls`
- `aria-describedby`
- `aria-labelledby`
+- `label[for]`
+- `input[list]`
+- `*[aria-controls]`
+- `*[aria-describedby]`
+- `*[aria-labelledby]`

 ## Rule details


--- a/docs/usage/elements.md
+++ b/docs/usage/elements.md
@@ -32,7 +32,7 @@ export interface MetaElement {
  interactive: boolean | PropertyExpression;

  /* element properties */
-  deprecated: boolean | string;
+  deprecated: boolean | string | DeprecatedElement;
  foreign: boolean;
  void: boolean;
  transparent: boolean;
@@ -101,8 +101,35 @@ The available evaluators are:

 ### `deprecated`

-If true the element will trigger the [deprecated](/rules/deprecated.html) rule
-when used. Can optionally be set to a string which will be displayed as well.
+If truthy the element will trigger the [deprecated](/rules/deprecated.html) rule
+when used.
+
+Can be set to `true`, a string or an object.
+
+```typescript
+interface DeprecatedElement {
+  message?: string;
+  documentation?: string;
+  source?: string;
+}
+```
+
+Setting `true` is the same as the empty object.
+Setting a string is the same as setting `message` to the string.
+
+If the `message` property is set the text will be displayed in the error message.
+
+If the `documentation` property is set the text will be rendered as markdown and shown in the contextual documentation shown by editors.
+`$tagname` can be used as a placeholder in the text.
+
+If the `source` property is set it is used to help the end-user to understand when and by what it is deprecated.
+It can be set to:
+
+- HTML major revision, e.g. `html5` or `html4`.
+- HTML minor revision, e.g. `html53` or `html32`.
+- `whatwg`: WHATWG Living Standard.
+- `non-standard`: non-standard element implemented only by one or few browsers.
+- your library or application name.

 ### `foreign`

@@ -169,13 +196,16 @@ An object with allowed attribute values.
 With this metadata the attribute `"foo"` may only have the values `"bar"` or
 `"foo"`.

- To allow empty values explicitly list `""`:  
-  `"my-attr": ["", "value 1", "value 2"]`
- Boolean attributes must be set to an empty list `[]`:  
-  `"my-attr": []`
-
 Regular expressions can also be used, e.g `"/-?\\d+/"` to match numbers.

+- To allow empty values explicitly list `""`:
+  - `"my-attr": ["", "value 1", "value 2"]`
+- Boolean attributes must be set to an empty list `[]` or include `""`:
+  - `"my-attr": []`
+  - `"my-attr": [""]`
+- To allow empty string `my-attr=""` but not omitted value `my-attr` use regexp:
+  - `"my-attr": ["/.*/"]`
+
 This is used by the
 [attribute-allowed-values](/rules/attribute-allowed-values.html) rule.


--- a/elements/__snapshots__/html5.spec.ts.snap
+++ b/elements/__snapshots__/html5.spec.ts.snap
@@ -3,7 +3,7 @@
 exports[`HTML elements <a> invalid markup 1`] = `
 Array [
  Object {
-    "errorCount": 4,
+    "errorCount": 5,
    "filePath": "test-files/elements/a-invalid.html",
    "messages": Array [
      Object {
@@ -50,6 +50,24 @@ Array [
        "severity": 2,
        "size": 1,
      },
+      Object {
+        "column": 4,
+        "context": Object {
+          "allowed": Array [
+            /\\.\\*/,
+          ],
+          "attribute": "href",
+          "element": "a",
+          "value": "",
+        },
+        "line": 12,
+        "message": "Attribute \\"href\\" is missing value",
+        "offset": 341,
+        "ruleId": "attribute-allowed-values",
+        "selector": "a:nth-child(5)",
+        "severity": 2,
+        "size": 4,
+      },
    ],
    "source": "<!-- should be transparent -->
 <span><a><div>foo</div></a></span>
@@ -60,6 +78,9 @@ Array [

 <!-- should not allow nesting -->
 <a><span><a>foo</a></span></a>
+
+<!-- should not allow omitted href value -->
+<a href>foo</a>
 ",
    "warningCount": 0,
  },
@@ -104,9 +125,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "\`<abbr>\` can be used as a replacement.",
+          "message": "use <abbr> instead",
+          "source": "html5",
+          "tagName": "acronym",
+        },
        "line": 2,
-        "message": "<acronym> is deprecated",
+        "message": "<acronym> is deprecated: use <abbr> instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "acronym",
@@ -214,7 +240,10 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "source": "html5",
+          "tagName": "applet",
+        },
        "line": 2,
        "message": "<applet> is deprecated",
        "offset": 32,
@@ -601,9 +630,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use CSS \`font-size\` property instead.",
+          "message": "use CSS instead",
+          "source": "html4",
+          "tagName": "basefont",
+        },
        "line": 2,
-        "message": "<basefont> is deprecated",
+        "message": "<basefont> is deprecated: use CSS instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "basefont",
@@ -685,9 +719,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use the \`<audio>\` element instead but consider accessibility concerns with autoplaying sounds.",
+          "message": "use <audio> instead",
+          "source": "non-standard",
+          "tagName": "bgsound",
+        },
        "line": 2,
-        "message": "<bgsound> is deprecated",
+        "message": "<bgsound> is deprecated: use <audio> instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "bgsound",
@@ -713,9 +752,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use CSS \`font-size\` property instead.",
+          "message": "use CSS instead",
+          "source": "html5",
+          "tagName": "big",
+        },
        "line": 2,
-        "message": "<big> is deprecated",
+        "message": "<big> is deprecated: use CSS instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "big",
@@ -741,7 +785,11 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "\`<blink>\` has no direct replacement and blinking text is frowned upon by accessibility standards.",
+          "source": "non-standard",
+          "tagName": "blink",
+        },
        "line": 2,
        "message": "<blink> is deprecated",
        "offset": 32,
@@ -1039,9 +1087,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use the CSS \`text-align\` or \`margin: auto\` properties instead.",
+          "message": "use CSS instead",
+          "source": "html4",
+          "tagName": "center",
+        },
        "line": 2,
-        "message": "<center> is deprecated",
+        "message": "<center> is deprecated: use CSS instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "center",
@@ -1429,7 +1482,11 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "The non-standard \`<dir>\` element has no direct replacement but MDN recommends replacing with \`<ul>\` and CSS.",
+          "source": "html4",
+          "tagName": "dir",
+        },
        "line": 2,
        "message": "<dir> is deprecated",
        "offset": 32,
@@ -1820,9 +1877,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use CSS font properties instead.",
+          "message": "use CSS instead",
+          "source": "html4",
+          "tagName": "font",
+        },
        "line": 2,
-        "message": "<font> is deprecated",
+        "message": "<font> is deprecated: use CSS instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "font",
@@ -1948,7 +2010,11 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "The \`<frame>\` element can be replaced with the \`<iframe>\` element but a better solution is to remove usage of frames entirely.",
+          "source": "html5",
+          "tagName": "frame",
+        },
        "line": 2,
        "message": "<frame> is deprecated",
        "offset": 32,
@@ -1994,7 +2060,11 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "The \`<frameset>\` element can be replaced with the \`<iframe>\` element but a better solution is to remove usage of frames entirely.",
+          "source": "html5",
+          "tagName": "frameset",
+        },
        "line": 2,
        "message": "<frameset> is deprecated",
        "offset": 32,
@@ -2538,7 +2608,9 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "tagName": "hgroup",
+        },
        "line": 2,
        "message": "<hgroup> is deprecated",
        "offset": 32,
@@ -3231,7 +3303,10 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "source": "html4",
+          "tagName": "isindex",
+        },
        "line": 2,
        "message": "<isindex> is deprecated",
        "offset": 32,
@@ -3481,7 +3556,7 @@ Array [
        "size": 4,
      },
      Object {
-        "column": 2,
+        "column": 21,
        "context": Object {
          "allowed": Array [
            /\\.\\+/,
@@ -3491,12 +3566,12 @@ Array [
          "value": "",
        },
        "line": 9,
-        "message": "Attribute \\"integrity\\" has invalid value \\"\\"",
-        "offset": 182,
+        "message": "Attribute \\"integrity\\" is missing value",
+        "offset": 201,
        "ruleId": "attribute-allowed-values",
        "selector": "link:nth-child(4)",
        "severity": 2,
-        "size": 4,
+        "size": 9,
      },
      Object {
        "column": 2,
@@ -3543,7 +3618,10 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "source": "html32",
+          "tagName": "listing",
+        },
        "line": 2,
        "message": "<listing> is deprecated",
        "offset": 32,
@@ -3607,7 +3685,11 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Marked as obsolete by both W3C and WHATWG standards but still implemented in most browsers. Animated text should be avoided for accessibility reasons as well.",
+          "source": "html5",
+          "tagName": "marquee",
+        },
        "line": 2,
        "message": "<marquee> is deprecated",
        "offset": 32,
@@ -3634,7 +3716,7 @@ Array [
    "filePath": "test-files/elements/math-invalid.html",
    "messages": Array [
      Object {
-        "column": 2,
+        "column": 7,
        "context": Object {
          "allowed": Array [
            "ltr",
@@ -3648,12 +3730,12 @@ Array [
          "value": "",
        },
        "line": 2,
-        "message": "Attribute \\"dir\\" has invalid value \\"\\"",
-        "offset": 32,
+        "message": "Attribute \\"dir\\" is missing value",
+        "offset": 37,
        "ruleId": "attribute-allowed-values",
        "selector": "math:nth-child(1)",
        "severity": 2,
-        "size": 4,
+        "size": 3,
      },
      Object {
        "column": 12,
@@ -3678,7 +3760,7 @@ Array [
        "size": 6,
      },
      Object {
-        "column": 2,
+        "column": 7,
        "context": Object {
          "allowed": Array [
            "block",
@@ -3689,12 +3771,12 @@ Array [
          "value": "",
        },
        "line": 4,
-        "message": "Attribute \\"display\\" has invalid value \\"\\"",
-        "offset": 77,
+        "message": "Attribute \\"display\\" is missing value",
+        "offset": 82,
        "ruleId": "attribute-allowed-values",
        "selector": "math:nth-child(3)",
        "severity": 2,
-        "size": 4,
+        "size": 7,
      },
      Object {
        "column": 16,
@@ -3716,7 +3798,7 @@ Array [
        "size": 6,
      },
      Object {
-        "column": 2,
+        "column": 7,
        "context": Object {
          "allowed": Array [
            "linebreak",
@@ -3730,12 +3812,12 @@ Array [
          "value": "",
        },
        "line": 6,
-        "message": "Attribute \\"overflow\\" has invalid value \\"\\"",
-        "offset": 130,
+        "message": "Attribute \\"overflow\\" is missing value",
+        "offset": 135,
        "ruleId": "attribute-allowed-values",
        "selector": "math:nth-child(5)",
        "severity": 2,
-        "size": 4,
+        "size": 8,
      },
      Object {
        "column": 17,
@@ -3857,9 +3939,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use CSS columns instead.",
+          "message": "use CSS instead",
+          "source": "html5",
+          "tagName": "multicol",
+        },
        "line": 2,
-        "message": "<multicol> is deprecated",
+        "message": "<multicol> is deprecated: use CSS instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "multicol",
@@ -3915,7 +4002,10 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "source": "html32",
+          "tagName": "nextid",
+        },
        "line": 2,
        "message": "<nextid> is deprecated",
        "offset": 32,
@@ -3943,9 +4033,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use CSS \`white-space\` property instead.",
+          "message": "use CSS instead",
+          "source": "non-standard",
+          "tagName": "nobr",
+        },
        "line": 2,
-        "message": "<nobr> is deprecated",
+        "message": "<nobr> is deprecated: use CSS instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "nobr",
@@ -3971,7 +4066,10 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "source": "non-standard",
+          "tagName": "noembed",
+        },
        "line": 2,
        "message": "<noembed> is deprecated",
        "offset": 32,
@@ -3999,7 +4097,10 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "source": "html5",
+          "tagName": "noframes",
+        },
        "line": 2,
        "message": "<noframes> is deprecated",
        "offset": 32,
@@ -4037,7 +4138,7 @@ Array [
        "size": 8,
      },
      Object {
-        "column": 2,
+        "column": 9,
        "context": Object {
          "allowed": Array [
            /\\.\\+/,
@@ -4047,12 +4148,12 @@ Array [
          "value": "",
        },
        "line": 7,
-        "message": "Attribute \\"integrity\\" has invalid value \\"\\"",
-        "offset": 131,
+        "message": "Attribute \\"integrity\\" is missing value",
+        "offset": 138,
        "ruleId": "attribute-allowed-values",
        "selector": "script:nth-child(2)",
        "severity": 2,
-        "size": 6,
+        "size": 9,
      },
      Object {
        "column": 2,
@@ -4456,9 +4557,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use the \`<pre>\` element or use CSS to set a monospace font.",
+          "message": "use <pre> or CSS instead",
+          "source": "html2",
+          "tagName": "plaintext",
+        },
        "line": 2,
-        "message": "<plaintext> is deprecated",
+        "message": "<plaintext> is deprecated: use <pre> or CSS instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "plaintext",
@@ -5116,9 +5222,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use CSS margin or padding instead.",
+          "message": "use CSS instead",
+          "source": "non-standard",
+          "tagName": "spacer",
+        },
        "line": 2,
-        "message": "<spacer> is deprecated",
+        "message": "<spacer> is deprecated: use CSS instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "spacer",
@@ -5172,9 +5283,14 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use the \`<del>\` or \`<s>\` element instead.",
+          "message": "use <del> or <s> instead",
+          "source": "html5",
+          "tagName": "strike",
+        },
        "line": 2,
-        "message": "<strike> is deprecated",
+        "message": "<strike> is deprecated: use <del> or <s> instead",
        "offset": 32,
        "ruleId": "deprecated",
        "selector": "strike",
@@ -6045,7 +6161,11 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use a more semantically correct element such as \`<code>\`, \`<var>\` or \`<pre>\`.",
+          "source": "html4",
+          "tagName": "tt",
+        },
        "line": 2,
        "message": "<tt> is deprecated",
        "offset": 32,
@@ -6315,7 +6435,11 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "Use \`<pre>\` or \`<code>\` and escape content using HTML entities instead.",
+          "source": "html32",
+          "tagName": "xmp",
+        },
        "line": 2,
        "message": "<xmp> is deprecated",
        "offset": 32,

--- a/elements/html5.json
+++ b/elements/html5.json
@@ -25,6 +25,10 @@
      "name",
      "urn"
    ],
+    "attributes": {
+      "download": ["", "/.+/"],
+      "href": ["/.*/"]
+    },
    "permittedDescendants": [{ "exclude": "@interactive" }]
  },

@@ -35,7 +39,11 @@
  },

  "acronym": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use <abbr> instead",
+      "documentation": "`<abbr>` can be used as a replacement.",
+      "source": "html5"
+    }
  },

  "address": {
@@ -47,7 +55,9 @@
  },

  "applet": {
-    "deprecated": true,
+    "deprecated": {
+      "source": "html5"
+    },
    "deprecatedAttributes": ["datasrc", "datafld"]
  },

@@ -102,7 +112,11 @@
  },

  "basefont": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use CSS instead",
+      "documentation": "Use CSS `font-size` property instead.",
+      "source": "html4"
+    }
  },

  "bdi": {
@@ -118,15 +132,26 @@
  },

  "bgsound": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use <audio> instead",
+      "documentation": "Use the `<audio>` element instead but consider accessibility concerns with autoplaying sounds.",
+      "source": "non-standard"
+    }
  },

  "big": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use CSS instead",
+      "documentation": "Use CSS `font-size` property instead.",
+      "source": "html5"
+    }
  },

  "blink": {
-    "deprecated": true
+    "deprecated": {
+      "documentation": "`<blink>` has no direct replacement and blinking text is frowned upon by accessibility standards.",
+      "source": "non-standard"
+    }
  },

  "blockquote": {
@@ -188,7 +213,11 @@
  },

  "center": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use CSS instead",
+      "documentation": "Use the CSS `text-align` or `margin: auto` properties instead.",
+      "source": "html4"
+    }
  },

  "cite": {
@@ -251,7 +280,10 @@
  },

  "dir": {
-    "deprecated": true
+    "deprecated": {
+      "documentation": "The non-standard `<dir>` element has no direct replacement but MDN recommends replacing with `<ul>` and CSS.",
+      "source": "html4"
+    }
  },

  "div": {
@@ -314,7 +346,11 @@
  },

  "font": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use CSS instead",
+      "documentation": "Use CSS font properties instead.",
+      "source": "html4"
+    }
  },

  "footer": {
@@ -337,13 +373,19 @@
  },

  "frame": {
-    "deprecated": true,
+    "deprecated": {
+      "documentation": "The `<frame>` element can be replaced with the `<iframe>` element but a better solution is to remove usage of frames entirely.",
+      "source": "html5"
+    },
    "deprecatedAttributes": ["datasrc", "datafld"],
    "requiredAttributes": ["title"]
  },

  "frameset": {
-    "deprecated": true
+    "deprecated": {
+      "documentation": "The `<frameset>` element can be replaced with the `<iframe>` element but a better solution is to remove usage of frames entirely.",
+      "source": "html5"
+    }
  },

  "h1": {
@@ -543,7 +585,9 @@
  },

  "isindex": {
-    "deprecated": true
+    "deprecated": {
+      "source": "html4"
+    }
  },

  "kbd": {
@@ -592,7 +636,9 @@
  },

  "listing": {
-    "deprecated": true
+    "deprecated": {
+      "source": "html32"
+    }
  },

  "main": {
@@ -612,7 +658,10 @@
  },

  "marquee": {
-    "deprecated": true,
+    "deprecated": {
+      "documentation": "Marked as obsolete by both W3C and WHATWG standards but still implemented in most browsers. Animated text should be avoided for accessibility reasons as well.",
+      "source": "html5"
+    },
    "deprecatedAttributes": ["datasrc", "datafld", "dataformatas"]
  },

@@ -643,7 +692,11 @@
  },

  "multicol": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use CSS instead",
+      "documentation": "Use CSS columns instead.",
+      "source": "html5"
+    }
  },

  "nav": {
@@ -654,19 +707,29 @@
  },

  "nextid": {
-    "deprecated": true
+    "deprecated": {
+      "source": "html32"
+    }
  },

  "nobr": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use CSS instead",
+      "documentation": "Use CSS `white-space` property instead.",
+      "source": "non-standard"
+    }
  },

  "noembed": {
-    "deprecated": true
+    "deprecated": {
+      "source": "non-standard"
+    }
  },

  "noframes": {
-    "deprecated": true
+    "deprecated": {
+      "source": "html5"
+    }
  },

  "noscript": {
@@ -788,7 +851,11 @@
  },

  "plaintext": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use <pre> or CSS instead",
+      "documentation": "Use the `<pre>` element or use CSS to set a monospace font.",
+      "source": "html2"
+    }
  },

  "pre": {
@@ -908,7 +975,11 @@
  },

  "spacer": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use CSS instead",
+      "documentation": "Use CSS margin or padding instead.",
+      "source": "non-standard"
+    }
  },

  "span": {
@@ -919,7 +990,11 @@
  },

  "strike": {
-    "deprecated": true
+    "deprecated": {
+      "message": "use <del> or <s> instead",
+      "documentation": "Use the `<del>` or `<s>` element instead.",
+      "source": "html5"
+    }
  },

  "strong": {
@@ -1124,7 +1199,10 @@
  },

  "tt": {
-    "deprecated": true
+    "deprecated": {
+      "documentation": "Use a more semantically correct element such as `<code>`, `<var>` or `<pre>`.",
+      "source": "html4"
+    }
  },

  "u": {
@@ -1166,6 +1244,9 @@
  },

  "xmp": {
-    "deprecated": true
+    "deprecated": {
+      "documentation": "Use `<pre>` or `<code>` and escape content using HTML entities instead.",
+      "source": "html32"
+    }
  }
 }
--- a/elements/html5.spec.ts
+++ b/elements/html5.spec.ts
@@ -153,8 +153,9 @@ describe("HTML elements", () => {
 			},
 		],
 		rules: {
-			/* allow any style of boolean attributes, some tests runs all of them */
+			/* allow any style of boolean/empty attributes, some tests runs all of them */
 			"attribute-boolean-style": "off",
+			"attribute-empty-style": "off",

 			/* messes with tests validating that elements with support implicit close
 			 * does so */

--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
 {
  "name": "html-validate",
-  "version": "2.17.1",
+  "version": "2.18.0",
  "description": "html linter",
  "keywords": [
    "html",
@@ -92,8 +92,8 @@
    "minimist": "^1.2.0"
  },
  "devDependencies": {
-    "@babel/core": "7.8.6",
-    "@babel/preset-env": "7.8.6",
+    "@babel/core": "7.8.7",
+    "@babel/preset-env": "7.8.7",
    "@commitlint/cli": "8.3.5",
    "@html-validate/commitlint-config": "1.0.1",
    "@html-validate/eslint-config": "1.1.4",
@@ -103,7 +103,7 @@
    "@types/estree": "0.0.42",
    "@types/glob": "7.1.1",
    "@types/inquirer": "6.5.0",
-    "@types/jest": "25.1.3",
+    "@types/jest": "25.1.4",
    "@types/json-merge-patch": "0.0.4",
    "@types/minimist": "1.2.0",
    "@types/node": "11.15.7",

--- a/src/__snapshots__/matchers.spec.ts.snap
+++ b/src/__snapshots__/matchers.spec.ts.snap
@@ -8,7 +8,7 @@ exports[`toBeToken() should fail if token doesn't match 1`] = `
 Expected token to equal:
  ObjectContaining {\\"type\\": \\"TAG_CLOSE\\"}
 Received:
-  {\\"data\\": [\\"<foo\\", \\"\\", \\"foo\\"], \\"location\\": {\\"column\\": 2, \\"filename\\": \\"inline\\", \\"line\\": 1, \\"offset\\": 1}, \\"type\\": 6}
+  {\\"data\\": [\\"<foo\\", \\"\\", \\"foo\\"], \\"location\\": {\\"column\\": 2, \\"filename\\": \\"inline\\", \\"line\\": 1, \\"offset\\": 1, \\"size\\": 1}, \\"type\\": 6}

 Difference:

@@ -28,6 +28,7 @@ Difference:
 +     \\"filename\\": \\"inline\\",
 +     \\"line\\": 1,
 +     \\"offset\\": 1,
+     \\"size\\": 1,
 +   },
 +   \\"type\\": 6,
  }"

--- a/src/config/__snapshots__/config-loader.spec.ts.snap
+++ b/src/config/__snapshots__/config-loader.spec.ts.snap
@@ -175,7 +175,11 @@ Array [
    "messages": Array [
      Object {
        "column": 2,
-        "context": undefined,
+        "context": Object {
+          "documentation": "\`<blink>\` has no direct replacement and blinking text is frowned upon by accessibility standards.",
+          "source": "non-standard",
+          "tagName": "blink",
+        },
        "line": 1,
        "message": "<blink> is deprecated",
        "offset": 1,
@@ -291,7 +295,9 @@ Array [
    "messages": Array [
      Object {
        "column": 3,
-        "context": undefined,
+        "context": Object {
+          "tagName": "deprecated",
+        },
        "line": 2,
        "message": "<deprecated> is deprecated",
        "offset": 8,

--- a/src/config/index.ts
+++ b/src/config/index.ts
 export { Config } from "./config";
 export { ConfigData, RuleConfig } from "./config-data";
 export { ConfigLoader } from "./config-loader";
+export { ConfigError } from "./error";
 export { Severity } from "./severity";
--- a/src/config/recommended.ts
+++ b/src/config/recommended.ts
@@ -4,6 +4,7 @@ module.exports = {
 		"attr-quotes": "error",
 		"attribute-allowed-values": "error",
 		"attribute-boolean-style": "error",
+		"attribute-empty-style": "error",
 		"close-attr": "error",
 		"close-order": "error",
 		deprecated: "error",

--- a/src/context/location.ts
+++ b/src/context/location.ts
@@ -21,10 +21,10 @@ export interface Location {
 	readonly column: number;

 	/**
-	 * If set it contains how many characters this location refers to. This
-	 * includes any whitespace characters such as newlines.
+	 * The number of characters this location refers to. This includes any
+	 * whitespace characters such as newlines.
 	 */
-	readonly size?: number;
+	readonly size: number;
 }

 interface LocationRW {
@@ -32,7 +32,7 @@ interface LocationRW {
 	offset: number;
 	line: number;
 	column: number;
-	size?: number;
+	size: number;
 }

 function sliceSize(size: number, begin: number, end?: number): number {

--- a/src/dom/htmlelement.spec.ts
+++ b/src/dom/htmlelement.spec.ts
@@ -655,6 +655,7 @@ describe("HtmlElement", () => {
 				offset: 0,
 				line: 1,
 				column: 1,
+				size: 1,
 			});
 			/* eslint-disable @typescript-eslint/no-unused-vars */
 			const a = new HtmlElement("a", root);

--- a/src/engine/engine.spec.ts
+++ b/src/engine/engine.spec.ts
@@ -31,6 +31,7 @@ class MockParser extends Parser {
 						line: 1,
 						column: 1,
 						offset: 0,
+						size: 1,
 					},
 					"invalid token error"
 				);
@@ -41,6 +42,7 @@ class MockParser extends Parser {
 						line: 1,
 						column: 1,
 						offset: 0,
+						size: 1,
 					},
 					"parser error"
 				);
@@ -110,7 +112,7 @@ describe("Engine", () => {
 				      "ruleId": "parser-error",
 				      "selector": null,
 				      "severity": 2,
-				      "size": 0,
+				      "size": 1,
 				    },
 				  ],
 				  "source": "invalid-token-error",
@@ -137,7 +139,7 @@ describe("Engine", () => {
 				      "ruleId": "parser-error",
 				      "selector": null,
 				      "severity": 2,
-				      "size": 0,
+				      "size": 1,
 				    },
 				  ],
 				  "source": "parser-error",

--- a/src/matchers.spec.ts
+++ b/src/matchers.spec.ts
@@ -167,6 +167,7 @@ describe("toBeToken()", () => {
 			line: 1,
 			column: 2,
 			offset: 1,
+			size: 1,
 		},
 	};


--- a/src/meta/element.ts
+++ b/src/meta/element.ts
@@ -14,6 +14,12 @@ export interface PermittedAttribute {
 	[key: string]: Array<string | RegExp>;
 }