Sync with twbs

.babelrc.js

@@ -1,16 +1,21 @@
 module.exports = {
   presets: [
     [
-      'env',
+      '@babel/env',
       {
         loose: true,
         modules: false,
-        exclude: ['transform-es2015-typeof-symbol']
+        exclude: ['transform-typeof-symbol']
       }
     ]
   ],
   plugins: [
-    process.env.ROLLUP && 'external-helpers',
-    process.env.PLUGINS && 'transform-es2015-modules-strip'
-  ].filter(Boolean)
+    process.env.PLUGINS && 'transform-es2015-modules-strip',
+    '@babel/proposal-object-rest-spread'
+  ].filter(Boolean),
+  env: {
+    test: {
+      plugins: [ 'istanbul' ]
+    }
+  }
 };

.eslintignore

@@ -1,3 +1,5 @@
 **/*.min.js
-**/vendor/*
-**/dist/*
+**/dist/
+**/vendor/
+/_gh_pages/
+/package.js

js/.eslintrc.json → .eslintrc.json

@@ -5,19 +5,13 @@
     "browser": true,
     "es6": true
   },
-  "extends": "eslint:recommended",
-  "plugins": ["compat"],
-  "parserOptions": {
-    "ecmaVersion": 8,
-    "sourceType": "module"
-  },
+  "extends": ["eslint:recommended", "plugin:compat/recommended"],
   "rules": {
     // Possible Errors
     "no-await-in-loop": "error",
     "no-extra-parens": "error",
     "no-prototype-builtins": "error",
     "no-template-curly-in-string": "error",
-    "compat/compat": "error",
     "valid-jsdoc": "error",
 
     // Best Practices
@@ -85,7 +79,7 @@
     "no-unused-expressions": "error",
     "no-useless-call": "error",
     "no-useless-concat": "error",
-    "no-useless-return": "off",
+    "no-useless-return": "error",
     "no-void": "error",
     "no-warning-comments": "off",
     "no-with": "error",
@@ -141,13 +135,12 @@
     "id-blacklist": "error",
     "id-length": "off",
     "id-match": "error",
-    "indent": "off",
-    "indent-legacy": ["error", 2, { "SwitchCase": 1 }],
+    "indent": ["error", 2, { "SwitchCase": 1 }],
     "jsx-quotes": "error",
     "key-spacing": "off",
     "keyword-spacing": "error",
-    "line-comment-position": "off",
     "linebreak-style": ["error", "unix"],
+    "line-comment-position": "off",
     "lines-around-comment": "off",
     "lines-around-directive": "error",
     "max-depth": ["error", 10],
@@ -159,10 +152,9 @@
     "max-statements-per-line": "error",
     "multiline-ternary": "off",
     "new-cap": ["error", { "capIsNewExceptionPattern": "$.*" }],
-    "new-parens": "error",
     "newline-after-var": "off",
-    "newline-before-return": "off",
     "newline-per-chained-call": ["error", { "ignoreChainWithDepth": 5 }],
+    "new-parens": "error",
     "no-array-constructor": "error",
     "no-bitwise": "error",
     "no-continue": "off",
@@ -171,6 +163,7 @@
     "no-mixed-operators": "off",
     "no-multi-assign": "error",
     "no-multiple-empty-lines": "error",
+    "nonblock-statement-body-position": "error",
     "no-negated-condition": "off",
     "no-nested-ternary": "error",
     "no-new-object": "error",
@@ -182,15 +175,15 @@
     "no-underscore-dangle": "off",
     "no-unneeded-ternary": "error",
     "no-whitespace-before-property": "error",
-    "nonblock-statement-body-position": "error",
     "object-curly-newline": ["error", { "minProperties": 1 }],
     "object-curly-spacing": ["error", "always"],
     "object-property-newline": "error",
     "one-var": ["error", "never"],
     "one-var-declaration-per-line": "error",
     "operator-assignment": "error",
-    "operator-linebreak": "off",
-    "padded-blocks": "off",
+    "operator-linebreak": "error",
+    "padded-blocks": ["error", "never"],
+    "padding-line-between-statements": "off",
     "quote-props": ["error", "as-needed"],
     "quotes": ["error", "single"],
     "require-jsdoc": "off",
@@ -200,8 +193,8 @@
     "sort-vars": "error",
     "space-before-blocks": "error",
     "space-before-function-paren": ["error", {
-        "anonymous": "always",
-        "named": "never"
+      "anonymous": "always",
+      "named": "never"
     }],
     "space-in-parens": "error",
     "space-infix-ops": "error",

.gitattributes

@@ -8,7 +8,9 @@
 *.scss  text eol=lf
 *.svg   text eol=lf
 *.txt   text eol=lf
+*.xml   text eol=lf
 *.yml   text eol=lf
+
 # Don't diff or textually merge source maps
 *.map   binary
 

.github/CONTRIBUTING.md

@@ -25,7 +25,7 @@ restrictions:
   respect the opinions of others.
 
 * Please **do not** post comments consisting solely of "+1" or ":thumbsup:".
-  Use [GitHub's "reactions" feature](https://github.com/blog/2119-add-reactions-to-pull-requests-issues-and-comments)
+  Use [GitHub's "reactions" feature](https://blog.github.com/2016-03-10-add-reactions-to-pull-requests-issues-and-comments/)
   instead. We reserve the right to delete comments which violate this rule.
 
 * Please **do not** open issues regarding the official themes offered on <https://themes.getbootstrap.com/>.
@@ -105,8 +105,8 @@ When feasible, we aim to report such upstream bugs to the relevant browser vendo
 | Vendor(s)     | Browser(s)                   | Rendering engine | Bug reporting website(s)                                                              | Notes                                                    |
 | ------------- | ---------------------------- | ---------------- | ------------------------------------------------------------------------------------- | -------------------------------------------------------- |
 | Mozilla       | Firefox                      | Gecko            | https://bugzilla.mozilla.org/enter_bug.cgi                                            | "Core" is normally the right product option to choose.   |
-| Apple         | Safari                       | WebKit           | https://bugs.webkit.org/enter_bug.cgi?product=WebKit <br> https://bugreport.apple.com | In Apple's bug reporter, choose "Safari" as the product. |
-| Google, Opera | Chrome, Chromium, Opera v15+ | Blink            | https://code.google.com/p/chromium/issues/list                                        | Click the "New issue" button.                            |
+| Apple         | Safari                       | WebKit           | https://bugs.webkit.org/enter_bug.cgi?product=WebKit <br> https://bugreport.apple.com/ | In Apple's bug reporter, choose "Safari" as the product. |
+| Google, Opera | Chrome, Chromium, Opera v15+ | Blink            | https://bugs.chromium.org/p/chromium/issues/list                                      | Click the "New issue" button.                            |
 | Microsoft     | Edge                         | EdgeHTML         | https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/                 |                                                          |
 
 ### Issues bots
@@ -178,7 +178,7 @@ included in the project:
    ```
 
 4. Commit your changes in logical chunks. Please adhere to these [git commit
-   message guidelines](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html)
+   message guidelines](https://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html)
    or your code is unlikely be merged into the main project. Use Git's
    [interactive rebase](https://help.github.com/articles/about-git-rebase/)
    feature to tidy up your commits before making them public.
@@ -204,15 +204,6 @@ includes code changes) and under the terms of the
 [Creative Commons Attribution 3.0 Unported License](docs/LICENSE)
 (if it includes documentation changes).
 
-### Pull request bots
-
-[@twbs-rorschach](https://github.com/twbs-rorschach) is a Bootstrap bot that hangs out in our GitHub issue tracker and automatically checks all pull requests for a few simple common mistakes. It's possible that Rorschach might leave a comment on your pull request and then close it. If that happens, simply fix the problem(s) mentioned in the comment (there should be link(s) in the comment explaining the problem(s) in detail) and then either:
-
-* Push the revised version to your pull request's branch and post a comment on the pull request saying that you've fixed the problem(s). One of the Bootstrap Core Team members will then come along and reopen your pull request.
-* Or you can just open a new pull request for your revised version.
-
-[@twbs-savage](https://github.com/twbs-savage) is a Bootstrap bot that automatically runs cross-browser tests (via [Sauce](https://saucelabs.com/) and Travis CI) on JavaScript pull requests. Savage will leave a comment on pull requests stating whether cross-browser JS tests passed or failed, with a link to the full Travis build details. If your pull request fails, check the Travis log to see which browser + OS combinations failed. Each browser test in the Travis log includes a link to a Sauce page with details about the test. On those details pages, you can watch a screencast of the test run to see exactly which unit tests failed.
-
 
 ## Code guidelines
 
@@ -229,7 +220,7 @@ includes code changes) and under the terms of the
 [Adhere to the Code Guide.](http://codeguide.co/#css)
 
 - When feasible, default color palettes should comply with [WCAG color contrast guidelines](https://www.w3.org/TR/WCAG20/#visual-audio-contrast).
-- Except in rare cases, don't remove default `:focus` styles (via e.g. `outline: none;`) without providing alternative styles. See [this A11Y Project post](http://a11yproject.com/posts/never-remove-css-outlines/) for more details.
+- Except in rare cases, don't remove default `:focus` styles (via e.g. `outline: none;`) without providing alternative styles. See [this A11Y Project post](https://a11yproject.com/posts/never-remove-css-outlines/) for more details.
 
 ### JS
 

.github/ISSUE_TEMPLATE/bug.md

@@ -0,0 +1,11 @@
+Before opening:
+
+- [Search for duplicate or closed issues](https://github.com/twbs/bootstrap/issues?utf8=%E2%9C%93&q=is%3Aissue)
+- [Validate](https://html5.validator.nu/) and [lint](https://github.com/twbs/bootlint#in-the-browser) any HTML to avoid common problems
+- Read the [contributing guidelines](https://github.com/twbs/bootstrap/blob/master/CONTRIBUTING.md)
+
+Bug reports must include:
+
+- Operating system and version (Windows, Mac OS X, Android, iOS, Win10 Mobile)
+- Browser and version (Chrome, Firefox, Safari, IE, MS Edge, Opera 15+, Android Browser)
+- [Reduced test case](https://css-tricks.com/reduced-test-cases/) and suggested fix using [CodePen](https://codepen.io/) or [JS Bin](https://jsbin.com/)

.github/ISSUE_TEMPLATE/feature.md

@@ -0,0 +1,9 @@
+Before opening:
+
+- [Search for duplicate or closed issues](https://github.com/twbs/bootstrap/issues?utf8=%E2%9C%93&q=is%3Aissue)
+- Read the [contributing guidelines](https://github.com/twbs/bootstrap/blob/master/CONTRIBUTING.md)
+
+Feature requests must include:
+
+- As much detail as possible for what we should add and why it's important to Bootstrap
+- Relevant links to prior art, screenshots, or live demos whenever possible

.github/SUPPORT.md

@@ -0,0 +1,11 @@
+### Bug reports
+
+See the [contributing guidelines](CONTRIBUTING.md) for sharing bug reports.
+
+### How-to
+
+For general troubleshooting or help getting started:
+
+- Join [the official Slack room](https://bootstrap-slack.herokuapp.com/).
+- Chat with fellow Bootstrappers in IRC. On the `irc.freenode.net` server, in the `##bootstrap` channel.
+- Ask and explore Stack Overflow with the [`bootstrap-4`](https://stackoverflow.com/questions/tagged/bootstrap-4) tag.

.gitignore

@@ -44,3 +44,4 @@ twbsconfig.yml
 
 # Folders to ignore
 node_modules
+js/coverage

.stylelintignore

@@ -0,0 +1,4 @@
+**/*.min.css
+**/dist/
+**/vendor/
+/_gh_pages/

build/.stylelintrc → .stylelintrc

@@ -4,9 +4,7 @@
     "stylelint-order"
   ],
   "rules": {
-    "at-rule-empty-line-before": [null,
-      "except": ["first-nested"]
-    ],
+    "at-rule-empty-line-before": null,
     "at-rule-name-space-after": "always",
     "at-rule-no-vendor-prefix": true,
     "at-rule-semicolon-space-before": "never",
@@ -33,6 +31,9 @@
     "no-descending-specificity": null,
     "no-duplicate-selectors": true,
     "number-leading-zero": "never",
+    "media-feature-name-no-unknown": [true, {
+      "ignoreMediaFeatureNames": ["prefers-reduced-motion"]
+    }],
     "order/properties-order": [
       "position",
       "top",
@@ -48,9 +49,11 @@
       "flex-direction",
       "flex-wrap",
       "flex-flow",
+      "flex-shrink",
       "flex-grow",
       "flex-order",
       "flex-pack",
+      "align-content",
       "align-items",
       "align-self",
       "justify-content",
@@ -79,6 +82,18 @@
       "-ms-overflow-x",
       "-ms-overflow-y",
       "-ms-overflow-style",
+      "columns",
+      "column-count",
+      "column-fill",
+      "column-gap",
+      "column-rule",
+      "column-rule-width",
+      "column-rule-style",
+      "column-rule-color",
+      "column-span",
+      "column-width",
+      "orphans",
+      "widows",
       "clip",
       "clear",
       "font",
@@ -94,6 +109,7 @@
       "font-emphasize-position",
       "font-emphasize-style",
       "font-smooth",
+      "src",
       "hyphens",
       "line-height",
       "color",
@@ -126,6 +142,8 @@
       "tab-size",
       "white-space",
       "vertical-align",
+      "direction",
+      "unicode-bidi",
       "list-style",
       "list-style-position",
       "list-style-type",
@@ -203,24 +221,33 @@
       "box-shadow",
       "opacity",
       "-ms-interpolation-mode",
+      "page-break-after",
+      "page-break-before",
+      "page-break-inside",
       "transition",
       "transition-delay",
       "transition-timing-function",
       "transition-duration",
       "transition-property",
       "transform",
       "transform-origin",
+      "perspective",
+      "appearance",
       "animation",
       "animation-name",
       "animation-duration",
       "animation-play-state",
       "animation-timing-function",
       "animation-delay",
       "animation-iteration-count",
-      "animation-direction"
+      "animation-direction",
+      "animation-fill-mode",
+      "fill",
+      "stroke"
     ],
     "property-no-vendor-prefix": true,
     "rule-empty-line-before": null,
+    "scss/dollar-variable-default": [true, { "ignore": "local" }],
     "selector-attribute-quotes": "always",
     "selector-list-comma-newline-after": "always",
     "selector-list-comma-newline-before": "never-multi-line",