fix: deduplicate Input objects in JSON

postcss · Dec 8, 2020 · c50d685 · c50d685
1 parent 7454de3
commit c50d685
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Showing 2 changed files with 29 additions and 15 deletions.
diff --git a/lib/fromJSON.js b/lib/fromJSON.js
@@ -8,16 +8,17 @@ let Input = require('./input')
 let Root = require('./root')
 let Rule = require('./rule')
 
-function fromJSON (json) {
-  let defaults = { ...json }
-  if (json.nodes) {
-    defaults.nodes = json.nodes.map(i => fromJSON(i))
+function fromJSON (json, inputs) {
+  let { _inputs, ...defaults } = json
+  inputs = _inputs || inputs
+  if (defaults.nodes) {
+    defaults.nodes = json.nodes.map(n => fromJSON(n, inputs))
   }
   if (defaults.source) {
     defaults.source = { ...defaults.source }
-    if (defaults.source.input) {
+    if (defaults.source.input != null) {
       defaults.source.input = {
-        ...defaults.source.input,
+        ...inputs[defaults.source.input],
         __proto__: Input.prototype
       }
       if (defaults.source.input.map) {
@@ -28,15 +29,15 @@ function fromJSON (json) {
       }
     }
   }
-  if (json.type === 'root') {
+  if (defaults.type === 'root') {
     return new Root(defaults)
-  } else if (json.type === 'decl') {
+  } else if (defaults.type === 'decl') {
     return new Declaration(defaults)
-  } else if (json.type === 'rule') {
+  } else if (defaults.type === 'rule') {
     return new Rule(defaults)
-  } else if (json.type === 'comment') {
+  } else if (defaults.type === 'comment') {
     return new Comment(defaults)
-  } else if (json.type === 'atrule') {
+  } else if (defaults.type === 'atrule') {
     return new AtRule(defaults)
   } else {
     throw new Error('Unknown node type: ' + json.type)

diff --git a/lib/node.js b/lib/node.js
@@ -166,8 +166,11 @@ class Node {
     if (!keepBetween) delete this.raws.between
   }
 
-  toJSON () {
+  toJSON (inputs) {
     let fixed = {}
+    let emitInputs = inputs == null
+    inputs = inputs || new Map()
+    let inputsNextIndex = 0
 
     for (let name in this) {
       if (!Object.prototype.hasOwnProperty.call(this, name)) {
@@ -180,23 +183,33 @@ class Node {
       if (Array.isArray(value)) {
         fixed[name] = value.map(i => {
           if (typeof i === 'object' && i.toJSON) {
-            return i.toJSON()
+            return i.toJSON(inputs)
           } else {
             return i
           }
         })
       } else if (typeof value === 'object' && value.toJSON) {
-        fixed[name] = value.toJSON()
+        fixed[name] = value.toJSON(inputs)
       } else if (name === 'source') {
+        let input = inputs.get(value.input)
+        if (input == null) {
+          input = inputsNextIndex
+          inputs.set(value.input, inputsNextIndex)
+          inputsNextIndex++
+        }
         fixed[name] = {
-          input: value.input.toJSON(),
+          input,
           start: value.start
         }
       } else {
         fixed[name] = value
       }
     }
 
+    if (emitInputs) {
+      fixed._inputs = [...inputs.keys()].map(input => input.toJSON())
+    }
+
     return fixed
   }