planning

node_modules/hast-util-to-mdast/index.js

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+'use strict'
+
+module.exports = toMdast
+
+var has = require('hast-util-has-property')
+var minify = require('rehype-minify-whitespace')
+var convert = require('unist-util-is/convert')
+var visit = require('unist-util-visit')
+var xtend = require('xtend')
+var one = require('./lib/one')
+var handlers = require('./lib/handlers')
+var own = require('./lib/util/own')
+
+var block = convert(['heading', 'paragraph', 'root'])
+
+function toMdast(tree, options) {
+  var settings = options || {}
+  var byId = {}
+  var mdast
+
+  h.nodeById = byId
+  h.baseFound = false
+  h.frozenBaseUrl = null
+  h.wrapText = true
+  h.qNesting = 0
+
+  h.handlers = settings.handlers ? xtend(handlers, settings.handlers) : handlers
+  h.augment = augment
+
+  h.document = settings.document
+  h.checked = settings.checked || '[x]'
+  h.unchecked = settings.unchecked || '[ ]'
+  h.quotes = settings.quotes || ['"']
+
+  visit(tree, 'element', onelement)
+
+  minify({newlines: settings.newlines === true})(tree)
+
+  mdast = one(h, tree, null)
+
+  visit(mdast, 'text', ontext)
+
+  return mdast
+
+  function h(node, type, props, children) {
+    var result
+
+    if (
+      !children &&
+      (typeof props === 'string' ||
+        (typeof props === 'object' && 'length' in props))
+    ) {
+      children = props
+      props = {}
+    }
+
+    result = xtend({type: type}, props)
+
+    if (typeof children === 'string') {
+      result.value = children
+    } else if (children) {
+      result.children = children
+    }
+
+    return augment(node, result)
+  }
+
+  // To do: inline in a future major.
+  // `right` is the finalized mdast node, created from `left`, a hast node.
+  function augment(left, right) {
+    if (left.position) {
+      right.position = left.position
+    }
+
+    return right
+  }
+
+  function onelement(node) {
+    var id = has(node, 'id') && String(node.properties.id).toUpperCase()
+
+    if (id && !own.call(byId, id)) {
+      byId[id] = node
+    }
+  }
+
+  // Collapse text nodes, and fix whitespace.
+  // Most of this is taken care of by `rehype-minify-whitespace`, but
+  // we’re generating some whitespace too, and some nodes are in the end
+  // ignored.
+  // So clean up:
+  function ontext(node, index, parent) {
+    var previous = parent.children[index - 1]
+
+    if (previous && node.type === previous.type) {
+      previous.value += node.value
+
+      parent.children.splice(index, 1)
+
+      if (previous.position && node.position) {
+        previous.position.end = node.position.end
+      }
+
+      // Iterate over the previous node again, to handle its total value.
+      return index - 1
+    }
+
+    node.value = node.value.replace(/[\t ]*(\r?\n|\r)[\t ]*/, '$1')
+
+    // We don’t care about other phrasing nodes in between (e.g., `[ asd ]()`),
+    // as there the whitespace matters.
+    if (block(parent)) {
+      if (!index) {
+        node.value = node.value.replace(/^[\t ]+/, '')
+      }
+
+      if (index === parent.children.length - 1) {
+        node.value = node.value.replace(/[\t ]+$/, '')
+      }
+    }
+
+    if (!node.value) {
+      parent.children.splice(index, 1)
+      return index
+    }
+  }
+}