feat(remark-table-of-content): don't overwrite existing property

remark/table-of-content/README.md

@@ -16,7 +16,7 @@ It supports CommonJS and ES modules.
 
 ## Simple usage
 
-This is a Remark plugin. As such, place the plugin after `remark-parse` and before `remark-rehype`.
+This is a Remark plugin. As such, place the plugin after `remark-parse` and before `remark-rehype`. Here is how to [return a `toc` property](./samples/simple-usage.js) with the table of content.
 
 ```js
 import assert from 'node:assert'
@@ -27,30 +27,26 @@ import remark2rehype from 'remark-rehype'
 import html from 'rehype-stringify'
 import pluginToc from '../lib/index.js'
 
+// Create a toc property
 const { toc } = await unified()
 .use(parseMarkdown)
-.use(pluginToc, {property: ['data', 'toc']})
+.use(pluginToc, {property: 'toc'})
 .use(remark2rehype)
 .use(html)
 .process(dedent`
-  ---
-  description: Using with frontmatter
-  ---
   # Heading 1
   ## Heading 2
 `)
-assert.deepEqual(toc, {
-  description: 'Using with frontmatter',
-  toc: [
-    { title: 'Heading 1', depth: 1, anchor: 'heading-1' },
-    { title: 'Heading 2', depth: 2, anchor: 'heading-2' }
-  ]
-})
+// Validation
+assert.deepEqual(toc, [
+  { title: 'Heading 1', depth: 1, anchor: 'heading-1' },
+  { title: 'Heading 2', depth: 2, anchor: 'heading-2' }
+])
 ```
 
 ## Using the `property` option
 
-The resulting array is returned with the `toc` property by default or any property of you like. For example, when used conjointly with the `remark-read-frontmatter` plugin, setting the `property` option to `['data', 'toc']` enriches the frontmatter `data` property.
+The resulting array is returned with the `toc` property by default or any property of you like. For example, when used conjointly with the `remark-read-frontmatter` plugin, setting the `property` option to `['data', 'toc']` [enriches the frontmatter `data` property](./samples/with-extract-frontmatter.js).
 
 
 ```js
@@ -86,3 +82,5 @@ assert.deepEqual(data, {
   ]
 })
 ```
+
+A value is preserved if the property is already exists in the vfile, for example in the frontmatter, 

remark/table-of-content/lib/index.js

@@ -1,49 +1,108 @@
 import { visit } from 'unist-util-visit'
 import slugify from '@sindresorhus/slugify'
+import { is_object_literal } from 'mixme'
+
+const get = (obj, keys, strict = false) => {
+  for (const key of keys) {
+    if (obj.hasOwnProperty(key)) {
+      obj = obj[key]
+    } else if (!strict) {
+      return undefined
+    } else {
+      throw Error('REMARK_TABLE_OF_CONTENT: property does not exists in strict mode.')
+    }
+  }
+  return obj
+}
+
+const set = (obj, keys, value, overwrite = false) => {
+  if( obj === null || typeof obj !== 'object' ) {
+    throw Error('REMARK_TABLE_OF_CONTENT: argument is not an object.')
+  }
+  for (let i = 0; i < keys.length; i++) {
+    const last = i === keys.length - 1
+    const key = keys[i]
+    if (!last) {
+      if (obj.hasOwnProperty(key)) {
+        // Move into the child
+        if (is_object_literal(obj[key])) {
+          obj = obj[key]
+        } else {
+          // Never overwrite a parent
+          throw Error(
+            'REMARK_TABLE_OF_CONTENT: cannot overwrite parent property.'
+          )
+        }
+      } else {
+        // Create the parent property
+        obj[key] = {}
+        obj = obj[key]
+      }
+    } else {
+      if (obj.hasOwnProperty(key)) {
+        // Move into the child
+        if (overwrite) {
+          obj[key] = value
+        } else {
+          // do nothing and preserve the origin value
+        }
+      } else {
+        // Create the parent property
+        obj[key] = value
+      }
+    }
+  }
+}
 
 export default function remarkToc({
   depth_min = 1,
   depth_max = 3,
   property = ['toc'],
 } = {}) {
-  if (typeof property === 'string'){
+  if (typeof property === 'string') {
     property = [property]
   }
   return function (tree, vfile) {
+    // if(get(vfile.data, property) === false) {
+    //   return
+    // }
     const toc = []
     visit(tree, 'heading', function (node) {
       if (node.depth < depth_min || node.depth > depth_max) return
       const title = node.children
-      .filter((child) => child.type === 'text' || child.type === 'strong' || child.type === 'emphasis' || child.type === 'inlineCode')
-      .map((child) => {
+        .filter(
+          (child) =>
+            child.type === 'text' ||
+            child.type === 'strong' ||
+            child.type === 'emphasis' ||
+            child.type === 'inlineCode'
+        )
+        .map((child) => {
           // when the text is bold or italic, the node.children[0] is not a text node but a strong or emphasis node
           // so we need to check the type of the node.children[0] to get the text value
           if (child.type === 'strong' || child.type === 'emphasis') {
             // case strong AND emphasis (***italic bold***) : the node.children[0] as an embedded node with the type strong or emphasis
-            if (child.children[0].type === 'strong' || child.children[0].type === 'emphasis') {
-              return child.children[0].children[0].value;
+            if (
+              child.children[0].type === 'strong' ||
+              child.children[0].type === 'emphasis'
+            ) {
+              return child.children[0].children[0].value
             }
-            return child.children[0].value;
-          } 
+            return child.children[0].value
+          }
           // but for inlineCode and text node, the value is directly in the child.value
-          return child.value;
+          return child.value
         })
-        .join('');
-      if (!title) return;
+        .join('')
+      if (!title) return
       toc.push({
         title: title,
         depth: node.depth,
         anchor: slugify(title),
-      });
+      })
     })
-    let mount = vfile
-    for(let i = 0; i < property.length - 1; i++){
-      const prop = property[i];
-      if(!mount[prop]){
-        mount[prop] = {}
-      }
-      mount = mount[prop]
-    }
-    mount[property[property.length - 1]] = toc
+    set(vfile, property, toc, false)
   }
 }
+
+export { get, set }

remark/table-of-content/package.json

@@ -16,6 +16,7 @@
     "@rollup/plugin-commonjs": "^25.0.3",
     "@rollup/plugin-node-resolve": "^15.1.0",
     "dedent": "^0.7.0",
+    "each": "^2.6.0",
     "rollup": "^3.26.3"
   },
   "exports": {

remark/table-of-content/sample/simple-usage.js → remark/table-of-content/samples/simple-usage.js

@@ -6,22 +6,18 @@ import remark2rehype from 'remark-rehype'
 import html from 'rehype-stringify'
 import pluginToc from '../lib/index.js'
 
+// Create a toc property
 const { toc } = await unified()
 .use(parseMarkdown)
-.use(pluginToc, {property: ['data', 'toc']})
+.use(pluginToc, {property: 'toc'})
 .use(remark2rehype)
 .use(html)
 .process(dedent`
-  ---
-  description: Using with frontmatter
-  ---
   # Heading 1
   ## Heading 2
 `)
-assert.deepEqual(toc, {
-  description: 'Using with frontmatter',
-  toc: [
-    { title: 'Heading 1', depth: 1, anchor: 'heading-1' },
-    { title: 'Heading 2', depth: 2, anchor: 'heading-2' }
-  ]
-})
+// Validation
+assert.deepEqual(toc, [
+  { title: 'Heading 1', depth: 1, anchor: 'heading-1' },
+  { title: 'Heading 2', depth: 2, anchor: 'heading-2' }
+])

remark/table-of-content/test/get.js

@@ -0,0 +1,27 @@
+import { get } from '../lib/index.js'
+
+describe('Utils `get`', () => {
+  // Note, get is not yet used by the library
+
+  it('valid path - level 1', async () => {
+    get({ a: 'value' }, ['a']).should.eql('value')
+  })
+
+  it('valid path - level 3 - value string', async () => {
+    get({ a: { b: { c: 'value' } } }, ['a', 'b', 'c']).should.eql('value')
+  })
+
+  it('valid path - level 3 - value `false`', async () => {
+    get({ a: { b: { c: false } } }, ['a', 'b', 'c']).should.eql(false)
+  })
+
+  it('get missing path - level 3 - relax', async () => {
+    should(get({}, ['a', 'b', 'c'])).eql(undefined)
+  })
+
+  it('get missing path - level 3 - strict', async () => {
+    ;(() => get({}, ['a', 'b', 'c'], true)).should.throw(
+      'REMARK_TABLE_OF_CONTENT: property does not exists in strict mode.'
+    )
+  })
+})

remark/table-of-content/test/index.js

@@ -121,6 +121,25 @@ describe('Extract table of content', () => {
       })
     })
 
+    it('preserve value if `false`', async () => {
+      const { data } = await unified()
+        .use(parseMarkdown)
+        .use(extractFrontmatter, ['yaml'])
+        .use(pluginReadFrontmatter)
+        .use(pluginToc, {property: ['data', 'toc']})
+        .use(remark2rehype)
+        .use(html).process(dedent`
+          ---
+          toc: false
+          ---
+          # Heading 1
+          ## Heading 2
+        `)
+      data.should.eql({
+        toc: false
+      })
+    })
+
   })
 
 })

remark/table-of-content/test/samples.js

@@ -0,0 +1,19 @@
+import each from 'each'
+import fs from 'fs'
+import path from 'path'
+import { exec } from 'child_process'
+
+const __dirname = new URL('.', import.meta.url).pathname
+const dir = path.resolve(__dirname, '../samples')
+const samples = fs.readdirSync(dir)
+
+describe('Samples', () => {
+
+  each(samples, true, (sample) => {
+    if (!/\.js$/.test(sample)) return
+    it(`Sample ${sample}`, (callback) => {
+      exec(`node ${path.resolve(dir, sample)}`, (err) => callback(err))
+    })
+  })
+
+})

remark/table-of-content/test/set.js

@@ -0,0 +1,35 @@
+import { set } from '../lib/index.js'
+
+describe('Utils `set`', () => {
+  it('valid path - property not yet defined - level 1', async () => {
+    const input = {}
+    set(input, ['a'], 'value')
+    input.should.eql({ a: 'value' })
+  })
+
+  it('valid path - property not yet defined - level 3', async () => {
+    const input = {}
+    set(input, ['a', 'b', 'c'], 'value')
+    input.should.eql({ a: { b: { c: 'value' } } })
+  })
+
+  it('fail to overwrite parent path', async () => {
+    const input = {'a': { 'b': true }}
+    ;( () =>
+      set(input, ['a', 'b', 'c'], 'value')
+    ).should.throw('REMARK_TABLE_OF_CONTENT: cannot overwrite parent property.')
+  })
+
+  it('value exists - level 3 - overwrite false', async () => {
+    const input = {'a': { 'b': { 'c': true} }}
+    set(input, ['a', 'b', 'c'], 'value')
+    input.should.eql({ a: { b: { c: true } } })
+  })
+
+  it('value exists - level 3 - overwrite false', async () => {
+    const input = {'a': { 'b': { 'c': true} }}
+    set(input, ['a', 'b', 'c'], 'value', { overwrite: true })
+    input.should.eql({ a: { b: { c: 'value' } } })
+  })
+
+})