Merge pull request #25 from Raynos/full-info

add getInfo() method

README.md

@@ -201,6 +201,8 @@ the type name.
  - `fullStack`; Take a wrapped error and compute a full stack.
  - `wrapf`; Utility function to quickly wrap
  - `errorf`; Utility function to quickly create an error
+ - `getInfo`; Utility function to get the info for any error
+object. Calls `err.info()` if the method exists.
 
 ### `WError`
 
@@ -326,6 +328,15 @@ and an info object.
 It will use [string-template][string-template] to apply the
 template with the `info` object as a parameter.
 
+### `SError.getInfo(error)`
+
+Static method to `getInfo` on a maybe error. The `error` can
+be `null` or `undefined`, it can be a plain `new Error()` or
+it can be a structured or wrapped error.
+
+Will return `err.info()` if it exists, returns `{}` if its `null`
+and returns `{ ...err }` if its a plain vanilla error.
+
 ### `serr.type`
 
 Returns the type field. The `err.type` field is machine readable.

index.js

@@ -2,8 +2,15 @@
 
 const assert = require('assert')
 
-/**
- * @typedef {import('./interfaces').CustomError} CustomError
+/** @typedef {{
+      type?: string;
+      errno?: string;
+      syscall?: string;
+      cause?(): Error;
+      fullType?(this: CustomError): string;
+      info?(): Record<string, unknown>;
+      toJSON?(): Record<string, unknown>;
+    } & Error} CustomError
  */
 
 const nargs = /\{([0-9a-zA-Z_]+)\}/g
@@ -52,12 +59,12 @@ class StructuredError extends Error {
     this.__info = info
   }
 
-  /** @returns {{ [k: string]: unknown }} */
+  /** @returns {Record<string, unknown>} */
   info () {
     return { ...this.__info }
   }
 
-  /** @returns {{ [k: string]: unknown }} */
+  /** @returns {Record<string, unknown>} */
   toJSON () {
     return {
       ...this.__info,
@@ -73,9 +80,22 @@ class StructuredError extends Error {
     return getTypeNameCached(this.name)
   }
 
+  /**
+   * @param {CustomError | null} error
+   * @returns {Record<string, unknown>}
+   */
+  static getInfo (error) {
+    if (!error) return {}
+    if (typeof error.info !== 'function') {
+      return { ...error }
+    }
+
+    return error.info()
+  }
+
   /**
    * @param {string} messageTmpl
-   * @param {{ [k: string]: unknown }} [info]
+   * @param {Record<string, unknown>} [info]
    * @returns {StructuredError}
    */
   static create (messageTmpl, info) {
@@ -133,14 +153,14 @@ class WrappedError extends Error {
     return this.__cause
   }
 
-  /** @returns {{ [k: string]: unknown }} */
+  /** @returns {Record<string, unknown>} */
   info () {
     return WrappedError.fullInfo(this.cause(), this.__info)
   }
 
-  /** @returns {{ [k: string]: unknown }} */
+  /** @returns {Record<string, unknown>} */
   toJSON () {
-    /** @type {{ [k: string]: unknown }} */
+    /** @type {Record<string, unknown>} */
     let causeJSON
     if (typeof this.__cause.toJSON === 'function') {
       causeJSON = this.__cause.toJSON()
@@ -188,10 +208,10 @@ class WrappedError extends Error {
   /**
    * @param {CustomError | null} cause
    * @param {object} [info]
-   * @returns {{ [k: string]: unknown }}
+   * @returns {Record<string, unknown>}
    */
   static fullInfo (cause, info) {
-    /** @type {{ [k: string]: unknown } | undefined} */
+    /** @type {Record<string, unknown> | undefined} */
     let existing
     if (cause && typeof cause.info === 'function') {
       existing = cause.info()
@@ -351,6 +371,15 @@ function fullStack (err) {
 }
 exports.fullStack = fullStack
 
+/**
+ * @param {CustomError | null} error
+ * @returns {Record<string, unknown>}
+ */
+function getInfo (error) {
+  return StructuredError.getInfo(error)
+}
+exports.getInfo = getInfo
+
 /**
  * @param {string} messageTmpl
  * @param {Error} cause
@@ -364,7 +393,7 @@ exports.wrapf = wrapf
 
 /**
  * @param {string} messageTmpl
- * @param {{ [k: string]: unknown }} [info]
+ * @param {Record<string, unknown>} [info]
  * @returns {StructuredError}
  */
 function errorf (messageTmpl, info) {
@@ -407,10 +436,10 @@ function createTypeStr (name) {
 
 /**
  * @param {CustomError} cause
- * @returns {{ [k: string]: unknown }}
+ * @returns {Record<string, unknown>}
  */
 function getInfoForPlainError (cause) {
-  /** @type {{ [k: string]: unknown }} */
+  /** @type {Record<string, unknown>} */
   const info = {}
   for (const field of PLAIN_ERROR_FIELDS) {
     const v = reflectGet(cause, field)
@@ -431,7 +460,7 @@ function isError (err) {
 
 /**
  * @param {Error} err
- * @returns {{ [k: string]: unknown }}
+ * @returns {Record<string, unknown>}
  */
 function getJSONForPlainError (err) {
   const obj = getInfoForPlainError(err)
@@ -449,7 +478,7 @@ function getJSONForPlainError (err) {
  */
 /**
  * @param {string} string
- * @param {{ [k: string]: unknown }} [object]
+ * @param {Record<string, unknown>} [object]
  * @returns {string}
  */
 function stringTemplate (string, object) {

package.json

@@ -31,7 +31,7 @@
   "devDependencies": {
     "@pre-bundled/tape": "5.0.0",
     "@types/node": "13.13.4",
-    "npm-bin-deps": "1.7.0"
+    "npm-bin-deps": "1.8.2"
   },
   "licenses": [
     {

test/wrapped.js

@@ -12,10 +12,10 @@ test('can create a wrapped error', function t (assert) {
   class ServerListenFailedError extends WError {}
 
   /** @type {Error & { code?: string }} */
-  var err = new Error('listen EADDRINUSE')
+  const err = new Error('listen EADDRINUSE')
   err.code = 'EADDRINUSE'
 
-  var err2 = ServerListenFailedError.wrap(
+  const err2 = ServerListenFailedError.wrap(
     'server failed', err, {
       requestedPort: 3426,
       host: 'localhost'