Add unwindIgnoreEmptyArrays option.

In order to convert the generated CSV back to the most accurate JSON possible, the module must still insert `[]` for unwound empty array values. However, there are some legitimate cases where users want to be able to have the module ignore these values so that the generated CSV is a bit more user-friendly, depending on the data being converted. This new option allows users the ability to achieve this without impacting existing use cases, as the user has opted to specify an option which may impact the ability to convert the CSV back to JSON later on. Fixes #168
mrodrig · Aug 9, 2021 · ed53d52 · ed53d52
1 parent d754925
commit ed53d52
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Showing 8 changed files with 60 additions and 11 deletions.
diff --git a/lib/constants.json b/lib/constants.json
@@ -33,6 +33,7 @@
     "checkSchemaDifferences": false,
     "expandArrayObjects": false,
     "unwindArrays": false,
+    "unwindIgnoreEmptyArrays": false,
     "useDateIso8601Format": false,
     "useLocaleFormat": false,
     "parseValue": null,

diff --git a/lib/json2csv.js b/lib/json2csv.js
@@ -13,7 +13,8 @@ const Json2Csv = function(options) {
         deeksOptions = {
             expandArrayObjects: expandingWithoutUnwinding,
             ignoreEmptyArraysWhenExpanding: expandingWithoutUnwinding,
-            escapeNestedDots: true
+            escapeNestedDots: true,
+            ignoreEmptyArrays: options.unwindIgnoreEmptyArrays
         };
 
     /** HEADER FIELD FUNCTIONS **/
@@ -201,7 +202,7 @@ const Json2Csv = function(options) {
 
             // Unwind each of the documents at the given headerField
             params.headerFields.forEach((headerField) => {
-                params.records = utils.unwind(params.records, headerField);
+                params.records = utils.unwind(params.records, headerField, options);
             });
 
             return retrieveHeaderFields(params.records)

diff --git a/lib/utils.js b/lib/utils.js
@@ -216,7 +216,7 @@ function getNCharacters(str, start, n) {
  * @param item {any}
  * @param fieldPath {String}
  */
-function unwindItem(accumulator, item, fieldPath) {
+function unwindItem(accumulator, item, fieldPath, options) {
     const valueToUnwind = path.evaluatePath(item, fieldPath);
     let cloned = deepCopy(item);
 
@@ -227,7 +227,7 @@ function unwindItem(accumulator, item, fieldPath) {
         });
     } else if (Array.isArray(valueToUnwind) && valueToUnwind.length === 0) {
         // Push an empty string so the value is empty since there are no values
-        path.setPath(cloned, fieldPath, '');
+        path.setPath(cloned, fieldPath, options.unwindIgnoreEmptyArrays ? [] : '');
         accumulator.push(cloned);
     } else {
         accumulator.push(cloned);
@@ -240,10 +240,10 @@ function unwindItem(accumulator, item, fieldPath) {
  * @param field {String}
  * @returns {Array<any>}
  */
-function unwind(array, field) {
+function unwind(array, field, options) {
     const result = [];
     array.forEach((item) => {
-        unwindItem(result, item, field);
+        unwindItem(result, item, field, options);
     });
     return result;
 }

diff --git a/test/config/testCsvFilesList.js b/test/config/testCsvFilesList.js
@@ -32,6 +32,7 @@ const fs = require('fs'),
         {key: 'csvEmptyLastValue', file: '../data/csv/csvEmptyLastValue.csv'},
         {key: 'unwind', file: '../data/csv/unwind.csv'},
         {key: 'unwindEmptyArray', file: '../data/csv/unwindEmptyArray.csv'},
+        {key: 'unwindIgnoreEmptyArrays', file: '../data/csv/unwindIgnoreEmptyArrays.csv'},
         {key: 'unwindWithSpecifiedKeys', file: '../data/csv/unwindWithSpecifiedKeys.csv'},
         {key: 'withSpecifiedKeys', file: '../data/csv/withSpecifiedKeys.csv'},
         {key: 'localeFormat', file: '../data/csv/localeFormat.csv'},

diff --git a/test/config/testJsonFilesList.js b/test/config/testJsonFilesList.js
@@ -25,6 +25,7 @@ module.exports = {
     csvEmptyLastValue: require('../data/json/csvEmptyLastValue'),
     unwind: require('../data/json/unwind'),
     unwindEmptyArray: require('../data/json/unwindEmptyArray'),
+    unwindIgnoreEmptyArrays: require('../data/json/unwindIgnoreEmptyArrays'),
     localeFormat: require('../data/json/localeFormat'),
     invalidParsedValues: require('../data/json/invalidParsedValues'),
     firstColumnWrapCRLF: require('../data/json/firstColumnWrapCRLF.json'),

diff --git a/test/data/csv/unwindIgnoreEmptyArrays.csv b/test/data/csv/unwindIgnoreEmptyArrays.csv
@@ -0,0 +1,3 @@
+entities.id,entities.name,entities.siblings.entity.name,entities.siblings.relationship_set.relationships.relationship.name
+4,Zeus,Exo,Senior
+4,Zeus,Chrono,
diff --git a/test/data/json/unwindIgnoreEmptyArrays.json b/test/data/json/unwindIgnoreEmptyArrays.json
@@ -0,0 +1,33 @@
+[
+    {
+      "entities":
+        {
+          "id": 4,
+          "name": "Zeus",
+          "siblings": [
+            {
+              "entity": {
+                "name": "Exo"
+              },
+              "relationship_set": {
+                "relationships": [
+                  {
+                    "relationship": {
+                      "name": "Senior"
+                    }
+                  }
+                ]
+              }
+            },
+            {
+              "entity": {
+                "name": "Chrono"
+              },
+              "relationship_set": {
+                "relationships": []
+              }
+            }
+          ]
+        }
+    }
+]
diff --git a/test/json2csv.js b/test/json2csv.js
@@ -656,15 +656,24 @@ function runTests(jsonTestData, csvTestData) {
                 });
             });
 
+            // Test case for #168
+            it('should ignore empty arrays when specified when unwinding arrays', (done) => {
+                converter.json2csv(jsonTestData.unwindIgnoreEmptyArrays, (err, csv) => {
+                    if (err) done(err);
+                    csv.should.equal(csvTestData.unwindIgnoreEmptyArrays);
+                    done();
+                }, {
+                    expandArrayObjects: true,
+                    unwindArrays: true,
+                    unwindIgnoreEmptyArrays: true
+                });
+            });
+
             // Test case for #184
             it('should handle keys with nested dots when expanding and unwinding arrays', (done) => {
                 converter.json2csv(jsonTestData.nestedDotKeysWithArrayExpandedUnwound, (err, csv) => {
                     if (err) done(err);
-
-                    // Replace raw boolean values with quoted versions
-                    let expectedCsv = csvTestData.nestedDotKeysWithArrayExpandedUnwound;
-
-                    csv.should.equal(expectedCsv);
+                    csv.should.equal(csvTestData.nestedDotKeysWithArrayExpandedUnwound);
                     done();
                 }, {
                     expandArrayObjects: true,