feat: add optional chaining support

Closes #424
davidbonnet · Jan 2, 2021 · 8c3ef44 · 8c3ef44
1 parent 325fdb3
commit 8c3ef44
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Showing 4 changed files with 19 additions and 4 deletions.
diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -1,11 +1,11 @@
 {
   "name": "astring",
-  "version": "1.4.3",
+  "version": "1.4.4",
   "description": "JavaScript code generator from an ESTree-compliant AST.",
   "main": "./dist/astring.js",
   "module": "./src/astring.js",
   "bin": {
-    "astring": "./bin/astring"
+    "astring": "bin/astring"
   },
   "scripts": {
     "build": "babel src/astring.js --out-file dist/astring.js --source-maps --no-comments",

diff --git a/src/astring.js b/src/astring.js
@@ -68,6 +68,7 @@ const EXPRESSIONS_PRECEDENCE = {
   SequenceExpression: 20,
   // Operations
   MemberExpression: 19,
+  ChainExpression: 19,
   CallExpression: 19,
   NewExpression: 19,
   // Other definitions
@@ -918,8 +919,14 @@ export const baseGenerator = {
     } else {
       this[node.callee.type](node.callee, state)
     }
+    if (node.optional) {
+      state.write('?.')
+    }
     formatSequence(state, node['arguments'])
   },
+  ChainExpression(node, state) {
+    this[node.expression.type](node.expression, state)
+  },
   MemberExpression(node, state) {
     if (
       EXPRESSIONS_PRECEDENCE[node.object.type] <
@@ -932,11 +939,18 @@ export const baseGenerator = {
       this[node.object.type](node.object, state)
     }
     if (node.computed) {
+      if (node.optional) {
+        state.write('?.')
+      }
       state.write('[')
       this[node.property.type](node.property, state)
       state.write(']')
     } else {
-      state.write('.')
+      if (node.optional) {
+        state.write('?.')
+      } else {
+        state.write('.')
+      }
       this[node.property.type](node.property, state)
     }
   },

diff --git a/src/tests/fixtures/syntax/object.js b/src/tests/fixtures/syntax/object.js
@@ -27,3 +27,4 @@ let i = {
   ...d,
   a
 };
+a?.['b']?.[0]?.(1);
-Original file line number
+Diff line change
@@ Expand Up / @@ -27,3 +27,4 @@ let i = { @@
       ...d,
       a
     };
+    a?.['b']?.[0]?.(1);