idx - npm Package Compare versions

Comparing version 1.5.0 to 2.1.0

lib/idx.js

@@ -64,5 +64,5 @@ /**
     if (error instanceof TypeError) {
-      if (isNullPropertyAccessError(error)) {
+      if (nullPattern.test(error)) {
         return null;
-      } else if (isUndefinedPropertyAccessError(error)) {
+      } else if (undefinedPattern.test(error)) {
         return undefined;
@@ -75,28 +75,16 @@ }
 
-var nullPattern = void 0;
-function isNullPropertyAccessError(_ref) {
-  var message = _ref.message;
-
-  if (!nullPattern) {
-    nullPattern = getInvalidPropertyAccessErrorPattern(null);
-  }
-  return nullPattern.test(message);
-}
-
-var undefinedPattern = void 0;
-function isUndefinedPropertyAccessError(_ref2) {
-  var message = _ref2.message;
-
-  if (!undefinedPattern) {
-    undefinedPattern = getInvalidPropertyAccessErrorPattern(undefined);
-  }
-  return undefinedPattern.test(message);
-}
-
 /**
- * Use `new Function(...)` to avoid minifying "$object$" and "$property$".
+ * Some actual error messages for null:
+ *
+ * TypeError: Cannot read property 'bar' of null
+ * TypeError: Cannot convert null value to object
+ * TypeError: foo is null
+ * TypeError: null has no properties
+ * TypeError: null is not an object (evaluating 'foo.bar')
+ * TypeError: null is not an object (evaluating '(" undefined ", null).bar')
  */
-// eslint-disable-next-line no-new-func, flowtype/no-weak-types
-var getInvalidPropertyAccessErrorPattern = new Function('$object$', '\n  try {\n    $object$.$property$;\n  } catch (error) {\n    return new RegExp(\n      error.message\n        .replace(/[-\\[\\]\\/\\{\\}\\(\\)\\*\\+\\?\\.\\\\\\^\\$\\|]/g, \'\\\\$&\')\n        .replace(\'\\\\$object\\\\$\', \'.+\')\n        .replace(\'\\\\$property\\\\$\', \'.+\')\n    );\n  }\n  throw new Error(\'Expected property access on \' + $object$ + \' to throw.\');\n');
+var nullPattern = /^null | null$|^[^\(]* null /;
+var undefinedPattern = /^undefined | undefined$|^[^\(]* undefined /;
 
+idx.default = idx;
 module.exports = idx;

package.json

 {
   "name": "idx",
-  "version": "1.5.0",
+  "version": "2.1.0",
   "description": "Utility function for traversing properties on objects and arrays.",
@@ -5,0 +5,0 @@ "main": "lib/idx.js",

README.md

@@ -9,8 +9,11 @@ # idx [![Circle Status](https://circleci.com/gh/facebookincubator/idx/tree/master.svg?style=shield&circle-token=da61f3cf105f22309c8ca0ba4482daa538bf5349)](https://circleci.com/gh/facebookincubator/idx)
 
+This module exists as a stop-gap solution because JavaScript does not currently
+support [optional chaining](https://github.com/tc39/proposal-optional-chaining).
+
 ## Usage
 
-Consider the following type:
+Consider the following type for `props`:
 
 ```javascript
-const props: {
+type User = {
   user: ?{
@@ -41,2 +44,16 @@ name: string,
 
+## Flow Type
+
+[Flow](https://flow.org/) understands the `idx` idiom:
+
+```javascript
+// @flow
+
+import idx from 'idx';
+
+function getName(props: User): ?string {
+  return idx(props, _ => _.user.name);
+}
+```
+
 ## Babel Transform
@@ -46,14 +63,41 @@
 behavior and is not meant to be executed. The `idx` function is used in
-conjunction with a Babel plugin that replaces it with better performing code:
+conjunction with a Babel plugin that replaces it with better performing code.
 
+This babel plugin searches for requires or imports to the `idx` module and
+replaces all its usages, so this code:
+
 ```javascript
-props.user == null ? props.user :
-props.user.friends == null ? props.user.friends :
-props.user.friends[0] == null ? props.user.friends[0] :
-props.user.friends[0].friends
+import idx from 'idx';
+
+function getFriends() {
+  return idx(props, _ => _.user.friends[0].friends)
+};
 ```
 
-All this machinery exists due to the fact that an existential operator does not
-currently exist in JavaScript.
+gets transformed to something like:
 
+```javascript
+function getFriends() {
+  props.user == null ? props.user :
+  props.user.friends == null ? props.user.friends :
+  props.user.friends[0] == null ? props.user.friends[0] :
+  return props.user.friends[0].friends
+}
+```
+
+(note that the original `import` gets also removed).
+
+It's possible to customize the name of the import/require, so code that is not
+directly requiring the `idx` npm package can also get transformed:
+
+```javascript
+{
+  plugins: [
+    ["babel-plugin-idx", {
+      importName: './idx',
+    }]
+  ]
+}
+```
+
 ## License
@@ -60,0 +104,0 @@

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Found 1 instance in 1 package

New author

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A new npm collaborator published a version of the package for the first time. New collaborators are usually benign additions to a project, but do indicate a change to the security surface area of a package.

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Fixed alerts

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Improved metrics

Total package byte prevSize

6154

increased by4.5%

Number of lines in readme file

104

increased by73.33%

Worsened metrics

Lines of code

83

decreased by-9.78%

Number of medium supply chain risk alerts

1

increased byInfinity%

No dependency changes