Initial commit

.editorconfig

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+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+max_line_length = 100
+trim_trailing_whitespace = true
+
+[COMMIT_EDITMSG]
+max_line_length = 72

.eslintrc.yaml

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+root: true
+extends:
+  - remcohaszing
+  - remcohaszing/jest
+rules:
+  import/extensions: off
+  import/no-extraneous-dependencies: off
+  import/no-unresolved: off
+
+  jsdoc/check-param-names: off
+  jsdoc/check-tag-names: off
+  jsdoc/require-jsdoc: off
+  jsdoc/require-property-type: off
+  jsdoc/valid-types: off
+
+  node/no-unpublished-import: off
+
+  unicorn/import-index: off

.github/workflows/ci.yaml

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+name: ci
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+    tags: ['*']
+
+jobs:
+  eslint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with: { node-version: 18 }
+      - run: npm ci
+      - run: npx eslint .
+
+  jest:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [14, 16, 18]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.version }}
+      - run: npm ci
+      - run: npx jest
+
+  pack:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with: { node-version: 18 }
+      - run: npm ci
+      - run: npm pack
+
+  prettier:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with: { node-version: 18 }
+      - run: npm ci
+      - run: npx prettier --check .
+
+  tsc:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with: { node-version: 18 }
+      - run: npm ci
+      - run: npx tsc

.gitignore

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+.next/
+coverage/
+node_modules/
+*.d.ts
+*.tgz
+tsconfig.tsbuildinfo

.npmrc

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+lockfile-version = 3

.prettierignore

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+.next/
+coverage/
+node_modules/
+*.d.ts
+*.tgz

.prettierrc.yaml

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+proseWrap: always
+semi: false
+singleQuote: true
+trailingComma: all

LICENSE.md

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+# MIT License
+
+Copyright © 2021 Remco Haszing
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial
+portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
+OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

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+# recma-nextjs-static-props
+
+> Expose top-level identifiers in Next.js app.js
+
+## Installation
+
+```sh
+npm install recma-nexjs-static-props
+```
+
+## Usage
+
+This plugin is intended for use with [Next.js](https://nextjs.org) and [MDX](https://mdxjs.com).
+
+```js
+import nextMDX from '@next/mdx'
+import recmaNextjsStaticProps from 'recma-nextjs-static-props'
+
+const withMDX = nextMDX({
+  options: {
+    recmaPlugins: [recmaNextjsStaticProps],
+  },
+})
+
+export default withMDX()
+```
+
+## API
+
+The default export is a recma plugin which exposes variables from the top-level scope in
+[Next.js](https://nextjs.org) through `getStaticProps`.
+
+### Options
+
+- `name`: The name of the export to generate. (Default: `'getStaticProps'`)
+- `include`: A list to filter identifiers to include in the generated function. This list may
+  include strings which must be matched exactly, a regular expression to test against, or a function
+  that will be called with the value to test, and must return a boolean. By default everything will
+  be included.
+- `exclude`: The same as `include`, but matching values will be excluded instead.
+
+## Example
+
+The source code repository for this plugin is setup as a [Next.js](https://nextjs.org) project.
+
+To try it yourself, simply clone, install, and run this project:
+
+```
+git clone https://github.com/remcohaszing/recma-nextjs-static-props.git
+cd recma-nextjs-static-props
+npm ci
+npm run dev
+```
+
+## Related Projects
+
+This plugin works well with the following [MDX](https://mdxjs.com) plugins:
+
+- [rehype-mdx-title](https://github.com/remcohaszing/rehype-mdx-title)
+- [remark-mdx-frontmatter](https://github.com/remcohaszing/remark-mdx-frontmatter)
+
+## License
+
+[MIT](LICENSE.md) © [Remco Haszing](https://github.com/remcohaszing)

components/PropsList.tsx

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+import { Fragment, ReactElement } from 'react'
+
+/**
+ * Render a list of available props.
+ */
+export function PropsList(props: Record<string, unknown>): ReactElement {
+  return (
+    <dl>
+      {Object.entries(props).map(([key, value]) => (
+        <Fragment key={key}>
+          <dt>{key}</dt>
+          <dd>
+            <pre>
+              <code>{JSON.stringify(value, undefined, 2)}</code>
+            </pre>
+          </dd>
+        </Fragment>
+      ))}
+    </dl>
+  )
+}

index.js

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+import { analyze } from 'periscopic'
+
+/**
+ * @typedef {RegExp | string | ((value: string) => boolean)} Test
+ */
+
+/**
+ * @typedef {Object} RecmaNextjsStaticPropsOptions
+ * @property {string} [name='getStaticProps']
+ * The name of the export to generate.
+ * @property {Test[]} [include]
+ * A list to filter identifiers to include in the generated function.
+ *
+ * This list may include strings which must be matched exactly, a regular expression to test
+ * against, or a function that will be called with the value to test, and must return a boolean. By
+ * default everything will be included.
+ * @property {Test[]} [exclude]
+ * The same as `include`, but matching values will be excluded instead.
+ */
+
+/**
+ * Check if a value matches a test.
+ *
+ * @param {Test} test - The test to match.
+ * @param {string} value - The value to match against the test.
+ * @returns {boolean} Whether or not the value matches the test.
+ */
+function passTest(test, value) {
+  if (typeof test === 'string') {
+    return value === test
+  }
+  if (test instanceof RegExp) {
+    return test.test(value)
+  }
+  return test(value)
+}
+
+/**
+ * A recma plugin which exposes variables from the top-level scope in Next.js through
+ * `getStaticProps`.
+ *
+ * @type {import('unified').Plugin<[RecmaNextjsStaticPropsOptions?], import('estree').Program>}
+ */
+const recmaNextjsStaticProps =
+  ({ exclude, include, name = 'getStaticProps' } = {}) =>
+  (ast) => {
+    /**
+     * @type {string[]}
+     */
+    const identifiers = []
+    const { scope } = analyze(ast)
+
+    for (const [id, node] of scope.declarations) {
+      if (id === name) {
+        return
+      }
+
+      // Always filter JSX functions generated by MDX.
+      if (id === '_jsx' || id === '_jsxs' || id === '_Fragment') {
+        continue
+      }
+
+      if (exclude && exclude.some((test) => passTest(test, id))) {
+        continue
+      }
+
+      if (include && !include.some((test) => passTest(test, id))) {
+        continue
+      }
+
+      // We’re not insterested in for example function or class declarations.
+      if (
+        node.type === 'ImportDefaultSpecifier' ||
+        node.type === 'ImportSpecifier' ||
+        node.type === 'VariableDeclaration'
+      ) {
+        identifiers.push(id)
+      }
+    }
+
+    if (!identifiers.length) {
+      return
+    }
+
+    ast.body.push({
+      type: 'ExportNamedDeclaration',
+      specifiers: [],
+      declaration: {
+        type: 'VariableDeclaration',
+        kind: 'const',
+        declarations: [
+          {
+            type: 'VariableDeclarator',
+            id: { type: 'Identifier', name },
+            init: {
+              type: 'ArrowFunctionExpression',
+              expression: true,
+              generator: false,
+              async: false,
+              params: [],
+              body: {
+                type: 'ObjectExpression',
+                properties: [
+                  {
+                    type: 'Property',
+                    method: false,
+                    shorthand: false,
+                    computed: false,
+                    kind: 'init',
+                    key: { type: 'Identifier', name: 'props' },
+                    value: {
+                      type: 'CallExpression',
+                      optional: false,
+                      callee: {
+                        type: 'MemberExpression',
+                        computed: false,
+                        optional: false,
+                        object: { type: 'Identifier', name: 'JSON' },
+                        property: { type: 'Identifier', name: 'parse' },
+                      },
+                      arguments: [
+                        {
+                          type: 'CallExpression',
+                          optional: false,
+                          callee: {
+                            type: 'MemberExpression',
+                            computed: false,
+                            optional: false,
+                            object: { type: 'Identifier', name: 'JSON' },
+                            property: { type: 'Identifier', name: 'stringify' },
+                          },
+                          arguments: [
+                            {
+                              type: 'ObjectExpression',
+                              properties: identifiers.sort().map((id) => ({
+                                type: 'Property',
+                                method: false,
+                                shorthand: true,
+                                computed: false,
+                                kind: 'init',
+                                key: { type: 'Identifier', name: id },
+                                value: { type: 'Identifier', name: id },
+                              })),
+                            },
+                          ],
+                        },
+                      ],
+                    },
+                  },
+                ],
+              },
+            },
+          },
+        ],
+      },
+    })
+  }
+
+export default recmaNextjsStaticProps