Completed tests for stringify

Author: develohpanda

src/stringify.ts

@@ -1,17 +1,35 @@
 import clonedeep from 'lodash.clonedeep';
 import { PropertyMap } from './models';
 
-const getProperty = (obj: object, key: string) => {
-  return key.split('.').filter((s) => s.length > 0)
-    .reduce((o: object, x: string) => o && o.hasOwnProperty(x) && o[x], obj);
+interface GetResult {
+  exists: boolean;
+  value: object;
+}
+
+const getProperty = (obj: object, key: string): GetResult => {
+  let exists = true;
+
+  const value = key.split('.')
+    .filter((s) => s.length > 0)
+    .reduce((o: object, x: string) => {
+      exists = o && o.hasOwnProperty(x);
+
+      if (!exists) {
+        return undefined;
+      }
+
+      return o[x];
+    }, obj);
+
+  return { exists, value };
 };
 
 const setProperty = (obj: object, key: string, value: object) => {
   key.split('.')
     .filter((s) => s.length > 0)
     .reduce((o: object, x: string, idx: number, src: Array<string>): object => {
       if (idx === src.length - 1) {
-        const valueToSet = Array.isArray(value) ? clonedeep(value) : value;
+        const valueToSet = Array.isArray(value) ? clonedeep(value).map((p) => typeof (p) === 'object' ? {} : p) : value;
         o[x] = valueToSet;
       }
 
@@ -20,8 +38,10 @@ const setProperty = (obj: object, key: string, value: object) => {
 };
 
 const copyProperty = (sourceObject: object, resultObject: object, propertyPath: string) => {
-  const value = getProperty(sourceObject, propertyPath);
-  setProperty(resultObject, propertyPath, value);
+  const result = getProperty(sourceObject, propertyPath);
+  if (result.exists) {
+    setProperty(resultObject, propertyPath, result.value);
+  }
 };
 
 const stringify = (sourceObject: object, map: PropertyMap): string => {
@@ -36,11 +56,15 @@ const stringify = (sourceObject: object, map: PropertyMap): string => {
 
     const parent = getProperty(sourceObject, parentKey);
 
-    // Set a default value for the property
-    setProperty(resultObject, parentKey, Array.isArray(parent) ? parent : {});
+    if (parent.exists) {
+      // Set a default value for the property
+      const defaultValue = Array.isArray(parent.value) ? parent.value : {};
+
+      setProperty(resultObject, parentKey, defaultValue);
 
-    // Fetch value from source and set on output
-    childKeys.forEach((key) => copyProperty(sourceObject, resultObject, `${parentKey}.${key}`));
+      // Fetch value from source and set on output
+      childKeys.forEach((key) => copyProperty(sourceObject, resultObject, `${parentKey}.${key}`));
+    }
   });
 
   return JSON.stringify(resultObject);

test/stringify.test.ts

@@ -1,9 +1,102 @@
+import { PropertyMap } from '../dist/models';
 import stringify from '../src/stringify';
 
 describe('stringify ', () => {
-  it('returns nothing for a blank JSON string', () => {
-    const result = stringify({}, {});
+  const expectString = (obj: object, map: PropertyMap, str: string) =>
+    expect(stringify(obj, map).replace(/\s/g, '')).toEqual(str);
 
-    expect(result).toEqual('{}');
-  });
+  it('returns nothing for a blank JSON string',
+    () => expectString(
+      {},
+      {},
+      '{}'));
+
+  it('ignores properties not found in source',
+    () => expectString(
+      {},
+      { $: ['a'] },
+      '{}'));
+
+  it('ignores properties not found in map',
+    () => expectString(
+      { a: '1', b: '2' },
+      { $: ['b'] },
+      '{"b":"2"}'));
+
+  it('returns first level object properties in order',
+    () => expectString(
+      { a: 2, b: 1 },
+      { $: ['b', 'a'] },
+      '{"b":1,"a":2}'));
+
+  it('returns first level array value in order',
+    () => expectString(
+      { a: ['2', 1, true] },
+      { $: ['a'] },
+      '{"a":["2",1,true]}'));
+
+  it('returns nested [array] > [object] properties in expected order',
+    () => expectString(
+      { a: [1, { c: '3', d: '2' }] },
+      { '$': ['a'], '$.a.1': ['d', 'c'] },
+      '{"a":[1,{"d":"2","c":"3"}]}'));
+
+  it('ignores nested [array] > [object] properties not found in map',
+    () => expectString(
+      { a: [1, { b: 2, c: 3 }, 4] },
+      { '$': ['a'], '$.a.1': ['c'] },
+      '{"a":[1,{"c":3},4]}'));
+
+  it('ignores nested [array] > [object] properties not found in map',
+    () => expectString(
+      { a: [1, { b: 2, c: 3 }, 4] },
+      { $: ['a'] },
+      '{"a":[1,{},4]}'));
+
+  it('returns nested [object] > [object] properties in expected order',
+    () => expectString(
+      {
+        a: {
+          b: {
+            c: 3, d: 4
+          },
+          e: {
+            f: 4, g: 5
+          },
+          h: 6
+        },
+        i: 7
+      },
+      {
+        '$': ['i', 'a'],
+        '$.a': ['e', 'h', 'b'],
+        '$.a.e': ['g', 'f'],
+        '$.a.b': ['d', 'c']
+      },
+      '{"i":7,"a":{"e":{"g":5,"f":4},"h":6,"b":{"d":4,"c":3}}}'));
+
+  it('returns nested [object] > [array] > [object] > [array] > [object] properties in expected order',
+    () => expectString(
+      {
+        a: {
+          b: [8, {
+            c: 9,
+            d: [{
+              e: 12,
+              f: {
+                g: true, h: 'h'
+              }
+            }, 10]
+          }, 11]
+        },
+        i: 7
+      },
+      {
+        '$': ['i', 'a'],
+        '$.a': ['b'],
+        '$.a.b.1': ['d', 'c'],
+        '$.a.b.1.d.0': ['f', 'e'],
+        '$.a.b.1.d.0.f': ['h', 'g']
+      },
+      '{"i":7,"a":{"b":[8,{"d":[{"f":{"h":"h","g":true},"e":12},10],"c":9},11]}}'));
 });