fix regression with de-structuring and default parameters (#149)

Author: gcanti

CHANGELOG.md

@@ -12,6 +12,11 @@
 **Note**: Gaps between patch versions are faulty/broken releases.
 **Note**: A feature tagged as Experimental is in a high state of flux, you're at risk of it changing without notice.
 
+# v0.3.23
+
+- **Bug Fix**
+  - fix regression with de-structuring and default parameters, fix #148 (@gcanti)
+
 # v0.3.22
 
 - **Bug Fix**

lib/index.js

@@ -24,6 +24,8 @@ exports.default = function (_ref) {
 
   var extendTemplate = expression('\n    function extendId(types, name) {\n      const isAny = (type) => {\n        if (type === tcombId.Any) {\n          return true;\n        }\n        if (tcombId.isType(type) && type.meta.kind === \'maybe\') {\n          return isAny(type.meta.type)\n        }\n        return false;\n      }\n      return tcombId.interface.extend(types.filter(type => !isAny(type)), name)\n    }\n  ');
 
+  var argumentsTemplate = expression('arguments[index] !== undefined ? arguments[index] : defaults');
+
   //
   // combinators
   //
@@ -367,12 +369,28 @@ exports.default = function (_ref) {
     return node;
   }
 
-  function getParam(isArrow, param, i) {
+  function getParamId(isArrow, param, i, defaults) {
+    if (t.isObjectPattern(param)) {
+      if (isArrow) {
+        return stripDefaults(param);
+      }
+      if (typeof defaults !== 'undefined') {
+        return argumentsTemplate({ index: t.identifier(i), defaults: defaults });
+      }
+      return t.memberExpression(t.identifier('arguments'), t.identifier(i), true);
+    }
+    if (t.isRestElement(param)) {
+      return param.argument;
+    }
+    return param;
+  }
+
+  function getParam(isArrow, param, i, defaults) {
     if (t.isAssignmentPattern(param) && param.left.typeAnnotation) {
-      return getParam(isArrow, param.left, i);
+      return getParam(isArrow, param.left, i, param.right);
     }
     if (param.typeAnnotation) {
-      var id = t.isObjectPattern(param) ? isArrow ? stripDefaults(param) : t.memberExpression(t.identifier('arguments'), t.identifier(i), true) : t.isRestElement(param) ? param.argument : param;
+      var id = getParamId(isArrow, param, i, defaults);
 
       return {
         id: id,

package.json

@@ -1,6 +1,6 @@
 {
   "name": "babel-plugin-tcomb",
-  "version": "0.3.22",
+  "version": "0.3.23",
   "description": "Babel plugin for static and runtime type checking using Flow and tcomb",
   "main": "lib/index.js",
   "files": [

src/index.js

@@ -94,6 +94,8 @@ export default function ({ types: t, template }) {
     }
   `)
 
+  const argumentsTemplate = expression(`arguments[index] !== undefined ? arguments[index] : defaults`)
+
   //
   // combinators
   //
@@ -462,17 +464,28 @@ export default function ({ types: t, template }) {
     return node
   }
 
-  function getParam(isArrow, param, i) {
+  function getParamId(isArrow, param, i, defaults) {
+    if (t.isObjectPattern(param)) {
+      if (isArrow) {
+        return stripDefaults(param)
+      }
+      if (typeof defaults !== 'undefined') {
+        return argumentsTemplate({ index: t.identifier(i), defaults })
+      }
+      return t.memberExpression(t.identifier('arguments'), t.identifier(i), true)
+    }
+    if (t.isRestElement(param)) {
+      return param.argument
+    }
+    return param
+  }
+
+  function getParam(isArrow, param, i, defaults) {
     if (t.isAssignmentPattern(param) && param.left.typeAnnotation) {
-      return getParam(isArrow, param.left, i)
+      return getParam(isArrow, param.left, i, param.right)
     }
     if (param.typeAnnotation) {
-      const id = t.isObjectPattern(param) ?
-          isArrow ?
-            stripDefaults(param) :
-            t.memberExpression(t.identifier('arguments'), t.identifier(i), true) :
-        t.isRestElement(param) ?
-          param.argument : param
+      const id = getParamId(isArrow, param, i, defaults)
 
       return {
         id,

test/fixtures/destructuring/expected.js

@@ -21,7 +21,7 @@ function bar({ a } = {}) {
 }
 
 function baz({ x: { y = "ex" } } = {}) {
-  _assert(arguments[0], _t.interface({
+  _assert(arguments[0] !== undefined ? arguments[0] : {}, _t.interface({
     x: _t.interface({
       y: _t.maybe(_t.String)
     })

test/index.js

@@ -212,7 +212,7 @@ describe('emit asserts for: ', () => {
     if ((caseName in skipTests)) {
       return
     }
-    if (!(caseName in { 'destructuring-with-arrows': 1 })) {
+    if (!(caseName in { 'destructuring': 1 })) {
       // return
     }
     it(`should ${caseName.split('-').join(' ')}`, () => {