adds support for prefix option, to put data on a controlled namespace

Author: jonschlinkert

lib/Expression.js

@@ -1,7 +1,6 @@
 'use strict';
 
 const ExpressionSync = require('./ExpressionSync');
-const transform = require('./transform');
 const variables = require('./variables');
 const utils = require('./utils');
 
@@ -136,7 +135,6 @@ class Expression extends ExpressionSync {
  async BinaryExpression(node, context) {
  const left = await this.visit(node.left, context, node);
  const right = () => this.visit(node.right, context, node);
-
  return this.comparison(left, node.operator, right, context, node);
  }
 
@@ -153,11 +151,16 @@ class Expression extends ExpressionSync {
  async ConditionalExpression(node, context) {
  const { test, consequent, alternate } = node;
  const truthy = await this.visit(test, context, node);
- return truthy ? await this.visit(consequent, context, node) : await this.visit(alternate, context, node);
+ return this.visit(truthy ? consequent : alternate, context, node);
  }
 
  async MemberExpression(node, context, parent) {
  const { computed, object, property, unset } = node;
+
+ if (object.name && this.options.prefix && !object.name.startsWith(this.options.prefix)) {
+ object.name = `${this.options.prefix}.${object.name}`;
+ }
+
  const value = (await this.visit(object, context, node)) ?? context[object.name];
  const data = computed ? context : value;
 
@@ -185,7 +188,13 @@ class Expression extends ExpressionSync {
  Object.assign(object, await this.visit(property, context, node));
  } else {
  const name = property.computed ? await this.visit(key, context, property) : (key.value || key.name);
- object[name] = await this.visit(value, context, property);
+ const result = await this.visit(value, context, property);
+
+ if (property.shorthand && this.options.prefix) {
+ property.shorthand = false;
+ }
+
+ object[name] = result;
  }
  }
 

lib/ExpressionSync.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const { default: getValue } = require('get-value');
 const FunctionsSync = require('./FunctionsSync');
 const Functions = require('./Functions');
 const variables = require('./variables');
@@ -57,11 +58,29 @@ class ExpressionSync {
  this.state.expressionDepth--;
  }
 
+ createContext(context) {
+ if (typeof context === 'function') {
+ return context;
+ }
+
+ if (utils.isPlainObject(context)) {
+ return { ...context };
+ }
+
+ return context;
+ }
+
  visit(node, context, parent) {
  this.incrementDepth();
 
  try {
- Reflect.defineProperty(node, 'parent', { value: node.parent || parent });
+ Reflect.defineProperty(node, 'parent', {
+ configurable: true,
+ enumerable: false,
+ writable: true,
+ value: node.parent || parent
+ });
+
  const visitor = this.visitors[node.type] || this[node.type];
 
  if (typeof visitor !== 'function') {
@@ -70,13 +89,19 @@ class ExpressionSync {
  throw new TypeError(message);
  }
 
- const block = node.type === 'ArrayExpression' || node.type === 'ObjectExpression';
- if (block) this.stack.push(node);
+ // const block = node.type === 'ArrayExpression' || node.type === 'ObjectExpression';
+ const ignore = ['Identifier', 'BinaryExpression'];
+
+ if (!ignore.includes(node.type)) {
+ this.stack.push(node);
+ } else {
+ //
+ }
 
  const value = visitor.call(this, node, context, parent);
  const resolve = v => {
  if (v instanceof Promise) return v.then(v => resolve(v));
- if (block) this.stack.pop();
+ if (!ignore.includes(node.type)) this.stack.pop();
  if (this.state.fail) return;
  return v;
  };
@@ -95,7 +120,7 @@ class ExpressionSync {
  return node.operator === '=' && node.right?.operator === '~' && this.options.regexOperator !== false;
  }
 
- assignment(node)  {
+ assignment(node) {
  switch (node.operator) {
  case '=': // Assignment operator.
  case '*=': // Multiplication assignment.
@@ -119,14 +144,38 @@ class ExpressionSync {
  }
  }
 
- postfix(node, value) {
+ assignOperation(operator, left, right) {
+ switch (operator) {
+ case '=': return right;
+ case '+=': return left + right;
+ case '-=': return left - right;
+ case '*=': return left * right;
+ case '/=': return left / right;
+ case '%=': return left % right;
+ case '**=': return left ** right;
+ case '<<=': return left << right;
+ case '>>=': return left >> right;
+ case '>>>=': return left >>> right;
+ case '&=': return left & right;
+ case '^=': return left ^ right;
+ case '|=': return left | right;
+ case '&&=': return left && right;
+ case '||=': return left || right;
+ case '??=': return left ?? right;
+ default: {
+ throw new SyntaxError(`Assignment operator "${operator}" is not supported`);
+ }
+ }
+ }
+
+ postfix(node, value) {
  switch (node.operator) {
  case '++': return value + 1;
  case '--': return value - 1;
  }
  }
 
- prefix(node, value)  {
+ prefix(node, value) {
  switch (node.operator) {
  case '++': return value + 1;
  case '--': return value - 1;
@@ -139,6 +188,12 @@ class ExpressionSync {
  const unset = obj => {
  if (utils.isObject(obj)) {
  Reflect.deleteProperty(obj, node.property.name);
+
+ const name = node.object.name;
+ if (name && this.options.prefix && !name.startsWith(this.options.prefix)) {
+ node.object.name = `${this.options.prefix}.${node.object.name}`;
+ }
+
  context[node.object.name] = obj;
  return true;
  }
@@ -196,7 +251,7 @@ class ExpressionSync {
  // Equality operators
  case '!==': return left !== val();
  case '===': return left === val();
- case '!=': return left != val();  /* eslint-disable-line eqeqeq */
+ case '!=': return left != val(); /* eslint-disable-line eqeqeq */
  case '==': return left == val(); /* eslint-disable-line eqeqeq */
 
  // Bitwise shift operators
@@ -300,7 +355,7 @@ class ExpressionSync {
  ConditionalExpression(node, context) {
  const { test, consequent, alternate } = node;
  const truthy = this.visit(test, context, node);
- return truthy ? this.visit(consequent, context, node) : this.visit(alternate, context, node);
+ return this.visit(truthy ? consequent : alternate, context, node);
  }
 
  Identifier(node, context, parent) {
@@ -314,8 +369,25 @@ class ExpressionSync {
  return;
  }
 
+ if (this.options.prefix && !node.name.startsWith(this.options.prefix)) {
+ if (!this.insideFunction || !this.functionParams?.some(p => p.name === node.name)) {
+ node.name = `${this.options.prefix}.${node.name}`;
+ }
+ }
+
  if (context != null) {
- if (context[node.name] !== undefined) return context[node.name];
+ if (typeof context?.lookup === 'function') {
+ const value = context.lookup(node.name);
+ if (value !== undefined) {
+ return value;
+ }
+ }
+
+ const value = context[node.name] ?? getValue(context, node.name);
+ if (value !== undefined) {
+ return value;
+ }
+
  if (hasOwnProperty.call(context, node.name)) {
  return;
  }
@@ -325,6 +397,7 @@ class ExpressionSync {
  if (this.options.strict !== false) {
  throw new ReferenceError(`${node.name} is undefined`);
  }
+
  this.state.fail = true;
  return ExpressionSync.FAIL;
  };
@@ -352,6 +425,11 @@ class ExpressionSync {
 
  MemberExpression(node, context, parent) {
  const { computed, object, property, unset } = node;
+
+ if (object.name && this.options.prefix && !object.name.startsWith(this.options.prefix)) {
+ object.name = `${this.options.prefix}.${object.name}`;
+ }
+
  const value = this.visit(object, context, node) ?? context[object.name];
  const data = computed ? context : value;
 
@@ -370,7 +448,7 @@ class ExpressionSync {
  prop = this.visit(property, data, node);
  }
 
- if (prop == null && property.name && data) {
+ if (prop === undefined && property.name && data) {
  prop = data[property.name];
  }
 
@@ -395,11 +473,14 @@ class ExpressionSync {
  if (type === 'SpreadElement') {
  Object.assign(object, this.visit(property, context, node));
  } else {
- const name = property.computed
- ? this.visit(key, context, property)
- : (key.value || key.name);
+ const name = property.computed ? this.visit(key, context, property) : key.value || key.name;
+ const result = this.visit(value, context, property);
 
- object[name] = this.visit(value, context, property);
+ if (property.shorthand && this.options.prefix) {
+ property.shorthand = false;
+ }
+
+ object[name] = result;
  }
  }
 
@@ -457,9 +538,9 @@ class ExpressionSync {
 
  ThisExpression(node, context) {
  if (!context) throw new TypeError('Cannot read property "this" of undefined');
- if (Reflect.has(context, 'this')) {
-  return context['this'];
- }
+
+ const thisKey = this.options.prefix ? `${this.options.prefix}.this` : 'this';
+ return getValue(context, thisKey) ?? getValue(context, 'this');
  }
 
  UnaryExpression(node, context) {
@@ -486,12 +567,22 @@ class ExpressionSync {
 
  const update = v => {
  const updated = node.prefix ? this.prefix(node, v) : this.postfix(node, v);
+
+ const name = node.argument.name;
+ if (name && this.options.prefix && !name.startsWith(this.options.prefix)) {
+ node.argument.name = `${this.options.prefix}.${node.argument.name}`;
+ }
+
  context[node.argument.name] = updated;
  return updated;
  };
 
  return value instanceof Promise ? value.then(obj => update(obj)) : update(value);
  }
+
+ ExpressionStatement(node, context) {
+ return this.visit(node.expression, context, node);
+ }
 }
 
 module.exports = ExpressionSync;