feat: Added the ability to populate truncated data with a default value.

Add optional replacement value for truncated values

Author: mrsteele

README.md

@@ -26,6 +26,10 @@ npm install json-truncate --save
 JSON.truncate = require('json-truncate');
 
 console.log(JSON.truncate(SomeDeepObject, 10));
+
+//OR specify a replacement string for truncated values
+
+console.log(JSON.truncate(SomeDeepObject, 10, {replace: '[Truncated]'}));
 ```
 
 ## Returns
@@ -36,6 +40,13 @@ You will get a proper truncated object that can now be written to a file if need
 
 * `obj` - The Object that will be truncated.
 * `maxDepth` - (optional) The depth at which to stop building the valid json. Defaults to `10`.
+* `options` - (optional) An option object to customize the behavior of the utility. Defaults to `{}`.
+
+**Current Option Properties**
+
+|Option|Description|
+|:--|:--|
+|**replace**|A string value that is used to replace all truncated values. If this value is not a string then all truncated values will be replaced with `undefined`|
 
 
 ## Licence

src/json-truncate.js

@@ -10,9 +10,11 @@ const isFlat = val => {
   return !isDefined(val) || flatTypes.indexOf(val.constructor) !== -1
 }
 
-const truncate = (obj, maxDepth, curDepth) => {
+const truncate = (obj, maxDepth, options, curDepth) => {
   curDepth = curDepth || 0
   maxDepth = (isDefined(maxDepth)) ? maxDepth : 10
+  options = (typeof options === 'object') ? options : {}
+  options.replace = (typeof options.replace === 'string') ? options.replace : undefined
 
   if (curDepth < maxDepth) {
     const newDepth = curDepth + 1
@@ -25,7 +27,7 @@ const truncate = (obj, maxDepth, curDepth) => {
         if (isFlat(value)) {
           newArr.push(value)
         } else {
-          newArr.push(truncate(value, maxDepth, newDepth))
+          newArr.push(truncate(value, maxDepth, options, newDepth))
         }
       })
       return newArr
@@ -35,12 +37,13 @@ const truncate = (obj, maxDepth, curDepth) => {
         if (isFlat(obj[key])) {
           newObj[key] = obj[key]
         } else {
-          newObj[key] = truncate(obj[key], maxDepth, newDepth)
+          newObj[key] = truncate(obj[key], maxDepth, options, newDepth)
         }
       }
       return newObj
     }
   }
+  return options.replace
 }
 
 export default truncate

test/mocha.spec.js

@@ -13,7 +13,7 @@ import dist from '../dist/json-truncate'
 const entry = require('../')
 
 // Helper
-const createDeep = levels => {
+const createDeep = (levels, replace) => {
   const createALevel = (obj, level) => {
     obj.bool = true
     obj.num = 10
@@ -35,8 +35,8 @@ const createDeep = levels => {
     if (levelsCopy > 0) {
       refobj = refobj.sub
     } else {
-      refobj.sub = undefined
-      refobj.arr = undefined
+      refobj.sub = replace
+      refobj.arr = replace
     }
   }
 
@@ -57,6 +57,16 @@ const createTestsFor = (m, name) => {
       m([createDeep(3)], 2).should.deep.equal([createDeep(1)])
     })
 
+    it('should truncate arrays and nested objects with replacement string', () => {
+      const replacement = '[replaced]'
+      m([createDeep(3, replacement)], 2, {replace: replacement}).should.deep.equal([createDeep(1, replacement)])
+    })
+
+    it('should replace truncated values with undefined when replace prop is not a string', () => {
+      const replacement = 3
+      m([createDeep(3)], 2, {replace: replacement}).should.deep.equal([createDeep(1)])
+    })
+
     it('should return flat objects', () => {
       ;[5, true, false, 'hello'].map(val => {
         m(val, 5).should.equal(val)