Create helper to get the object for a Value AST node, including proper non-AST location data

lib/coffeescript/nodes.js

@@ -1666,9 +1666,9 @@
       }
 
       isSplice() {
-        var lastProp, ref1;
-        ref1 = this.properties, [lastProp] = slice1.call(ref1, -1);
-        return lastProp instanceof Slice;
+        var lastProperty, ref1;
+        ref1 = this.properties, [lastProperty] = slice1.call(ref1, -1);
+        return lastProperty instanceof Slice;
       }
 
       looksStatic(className) {
@@ -1795,14 +1795,38 @@
         }
       }
 
+      // For AST generation, we need an `object` that’s this `Value` minus its last
+      // property, if it has properties.
+      object() {
+        var initialProperties, object;
+        if (!this.hasProperties()) {
+          return this;
+        }
+        // Get all properties except the last one; for a `Value` with only one
+        // property, `initialProperties` is an empty array.
+        initialProperties = this.properties.slice(0, this.properties.length - 1);
+        // Create the `object` that becomes the new “base” for the split-off final
+        // property.
+        object = new Value(this.base, initialProperties, this.tag, this.isDefaultValue);
+        // Add location data to our new node, so that it has correct location data
+        // for source maps or later conversion into AST location data.
+        // This new `Value` has only one property, so the location data is just
+        // that of the parent `Value`’s base.
+        // This new `Value` has multiple properties, so the location data spans
+        // from the parent `Value`’s base to the last property that’s included
+        // in this new node (a.k.a. the second-to-last property of the parent).
+        object.locationData = initialProperties.length === 0 ? this.base.locationData : mergeLocationData(this.base.locationData, initialProperties[initialProperties.length - 1].locationData);
+        return object;
+      }
+
       ast() {
         if (!this.hasProperties()) {
           // If the `Value` has no properties, the AST node is just whatever this
           // node’s `base` is.
           return this.base.ast();
         }
-        // Otherwise, call `Base::ast` which in turn calls the `astType`,
-        // `astProperties` and `astLocationData` methods below.
+        // Otherwise, call `Base::ast` which in turn calls the `astType` and
+        // `astProperties` methods below.
         return super.ast();
       }
 
@@ -1814,10 +1838,10 @@
       // becomes the `property`, and the preceding properties (e.g. `a.b`) become
       // a child `Value` node assigned to the `object` property.
       astProperties() {
-        var initialProperties, property, ref1, ref2;
-        ref1 = this.properties, [...initialProperties] = ref1, [property] = splice.call(initialProperties, -1);
+        var property, ref1, ref2;
+        ref1 = this.properties, [property] = slice1.call(ref1, -1);
         return {
-          object: new Value(this.base, initialProperties, this.tag, this.isDefaultValue).ast(),
+          object: this.object().ast(),
           property: property.ast(),
           computed: property instanceof Index || !(((ref2 = property.name) != null ? ref2.unwrap() : void 0) instanceof PropertyName),
           optional: !!property.soak,
@@ -1825,17 +1849,6 @@
         };
       }
 
-      // When the `Value` has properties, the location data of a
-      // `MemberExpression` AST node corresponding to a given property should
-      // span the location of the `Value`’s `base` (including parentheses if
-      // present) through the property’s location.
-      astLocationData() {
-        if (this.locationData != null) {
-          return super.astLocationData();
-        }
-        return mergeAstLocationData(this.base.astLocationData(), this.properties[this.properties.length - 1].astLocationData());
-      }
-
     };
 
     Value.prototype.children = ['base', 'properties'];
@@ -5199,9 +5212,9 @@
   //### In
   exports.In = In = (function() {
     class In extends Base {
-      constructor(object, array) {
+      constructor(object1, array) {
         super();
-        this.object = object;
+        this.object = object1;
         this.array = array;
       }
 

src/nodes.coffee

@@ -1097,8 +1097,8 @@ exports.Value = class Value extends Base
     @base.hasElision()
 
   isSplice: ->
-    [..., lastProp] = @properties
-    lastProp instanceof Slice
+    [..., lastProperty] = @properties
+    lastProperty instanceof Slice
 
   looksStatic: (className) ->
     (@this or @base instanceof ThisLiteral or @base.value is className) and
@@ -1186,12 +1186,36 @@ exports.Value = class Value extends Base
     else
       @error 'tried to assign to unassignable value'
 
+  # For AST generation, we need an `object` that’s this `Value` minus its last
+  # property, if it has properties.
+  object: ->
+    return @ unless @hasProperties()
+    # Get all properties except the last one; for a `Value` with only one
+    # property, `initialProperties` is an empty array.
+    initialProperties = @properties[0...@properties.length - 1]
+    # Create the `object` that becomes the new “base” for the split-off final
+    # property.
+    object = new Value @base, initialProperties, @tag, @isDefaultValue
+    # Add location data to our new node, so that it has correct location data
+    # for source maps or later conversion into AST location data.
+    object.locationData =
+      if initialProperties.length is 0
+        # This new `Value` has only one property, so the location data is just
+        # that of the parent `Value`’s base.
+        @base.locationData
+      else
+        # This new `Value` has multiple properties, so the location data spans
+        # from the parent `Value`’s base to the last property that’s included
+        # in this new node (a.k.a. the second-to-last property of the parent).
+        mergeLocationData @base.locationData, initialProperties[initialProperties.length - 1].locationData
+    object
+
   ast: ->
     # If the `Value` has no properties, the AST node is just whatever this
     # node’s `base` is.
     return @base.ast() unless @hasProperties()
-    # Otherwise, call `Base::ast` which in turn calls the `astType`,
-    # `astProperties` and `astLocationData` methods below.
+    # Otherwise, call `Base::ast` which in turn calls the `astType` and
+    # `astProperties` methods below.
     super()
 
   astType: -> 'MemberExpression'
@@ -1200,22 +1224,13 @@ exports.Value = class Value extends Base
   # becomes the `property`, and the preceding properties (e.g. `a.b`) become
   # a child `Value` node assigned to the `object` property.
   astProperties: ->
-    [initialProperties..., property] = @properties
-
-    object: new Value(@base, initialProperties, @tag, @isDefaultValue).ast()
-    property: property.ast()
-    computed: property instanceof Index or property.name?.unwrap() not instanceof PropertyName
-    optional: !!property.soak
-    shorthand: !!property.shorthand
-
-  # When the `Value` has properties, the location data of a
-  # `MemberExpression` AST node corresponding to a given property should
-  # span the location of the `Value`’s `base` (including parentheses if
-  # present) through the property’s location.
-  astLocationData: ->
-    return super() if @locationData?
-    mergeAstLocationData @base.astLocationData(),
-      @properties[@properties.length - 1].astLocationData()
+    [..., property] = @properties
+    return
+      object: @object().ast()
+      property: property.ast()
+      computed: property instanceof Index or property.name?.unwrap() not instanceof PropertyName
+      optional: !!property.soak
+      shorthand: !!property.shorthand
 
 #### HereComment