better handling of empty headers and dupes

.eslintrc.js

@@ -24,6 +24,7 @@ module.exports = {
     'prefer-destructuring': 0,
     'no-param-reassign': 0, // sometimes it's just much easier
     'lines-between-class-members': 0, // grouping related one-liners can be nice
+    'no-continue': 0,
   },
   overrides: [
     { // extra jest related rules for tests

docs/classes/google-spreadsheet.md

@@ -111,7 +111,7 @@ Param|Type|Required|Description
 ---|---|---|---
 `props`|Object|-|Object of all sheet properties
 `props.sheetId`|Number<br>_positive int_|-|Sheet ID, cannot be chagned after setting<br>_easiest to just let google handle it_
-`props.headers`|[String]|-|Sets the contents of the first row, to be used in row-based interactions
+`props.headerValues`|[String]|-|Sets the contents of the first row, to be used in row-based interactions
 `props.[more]`|...|-|_See [GoogleSpreadsheetWorksheet](classes/google-spreadsheet-worksheet#basic-document-properties) for more props_
 
 

lib/GoogleSpreadsheet.js

@@ -243,9 +243,9 @@ class GoogleSpreadsheet {
     const newSheetId = response.properties.sheetId;
     const newSheet = this.sheetsById[newSheetId];
 
-    if (properties.headers) {
-      await newSheet.setHeaderRow(properties.headers);
-    }
+    // allow it to work with `.headers` but `.headerValues` is the real prop
+    if (properties.headers) { await newSheet.setHeaderRow(properties.headers); }
+    if (properties.headerValues) { await newSheet.setHeaderRow(properties.headerValues); }
 
     return newSheet;
   }

lib/GoogleSpreadsheetRow.js

@@ -8,6 +8,7 @@ class GoogleSpreadsheetRow {
 
     for (let i = 0; i < this._sheet.headerValues.length; i++) {
       const propName = this._sheet.headerValues[i];
+      if (!propName) continue; // skip empty header
       Object.defineProperty(this, propName, {
         get: () => this._rawData[i],
         set: (newVal) => { this._rawData[i] = newVal; },

lib/GoogleSpreadsheetWorksheet.js

@@ -5,6 +5,17 @@ const GoogleSpreadsheetCell = require('./GoogleSpreadsheetCell');
 
 const { getFieldMask, columnToLetter, letterToColumn } = require('./utils');
 
+function checkForDuplicateHeaders(headers) {
+  // check for duplicate headers
+  const checkForDupes = _.groupBy(headers); // { c1: ['c1'], c2: ['c2', 'c2' ]}
+  _.each(checkForDupes, (grouped, header) => {
+    if (!header) return; // empty columns are skipped, so multiple is ok
+    if (grouped.length > 1) {
+      throw new Error(`Duplicate header detected: "${header}". Please make sure all non-empty headers are unique`);
+    }
+  });
+}
+
 class GoogleSpreadsheetWorksheet {
   constructor(parentSpreadsheet, { properties, data }) {
     this._spreadsheet = parentSpreadsheet; // the parent GoogleSpreadsheet instance
@@ -39,7 +50,7 @@ class GoogleSpreadsheetWorksheet {
 
   resetLocalCache(dataOnly) {
     if (!dataOnly) this._rawProperties = null;
-    this.headers = null;
+    this.headerValues = null;
     this._cells = [];
   }
 
@@ -266,16 +277,20 @@ class GoogleSpreadsheetWorksheet {
 
 
   // ROW BASED FUNCTIONS ///////////////////////////////////////////////////////////////////////////
+
   async loadHeaderRow() {
     const rows = await this.getCellsInRange(`A1:${this.lastColumnLetter}1`);
-    this.headerValues = rows[0];
+    this.headerValues = _.map(rows[0], (header) => header.trim());
+    checkForDuplicateHeaders(this.headerValues);
   }
 
   async setHeaderRow(headerValues) {
     if (!headerValues) return;
     if (headerValues.length > this.columnCount) {
       throw new Error(`Sheet is not large enough to fit ${headerValues.length} columns. Resize the sheet first.`);
     }
+    const trimmedHeaderValues = _.map(headerValues, (h) => h.trim());
+    checkForDuplicateHeaders(trimmedHeaderValues);
 
     const response = await this._spreadsheet.axios.request({
       method: 'put',
@@ -287,7 +302,7 @@ class GoogleSpreadsheetWorksheet {
       data: {
         range: `${this.a1SheetName}!A1`,
         majorDimension: 'ROWS',
-        values: [headerValues],
+        values: [trimmedHeaderValues],
       },
     });
     this.headerValues = response.data.updatedData.values[0];

package.json

@@ -2,7 +2,7 @@
   "author": "Theo Ephraim <theozero@gmail.com> (https://theoephraim.com)",
   "name": "google-spreadsheet",
   "description": "Google Sheets API (v4) -- simple interface to read/write data and manage sheets",
-  "version": "3.0.2",
+  "version": "3.0.3",
   "license": "Unlicense",
   "keywords": [
     "google spreadsheets",

test/manage.test.js

@@ -194,7 +194,7 @@ describe('Managing doc info and sheets', () => {
       const copiedSheet = docs.public.sheetsByIndex.splice(-1)[0];
       expect(copiedSheet.title).toBe(`Copy of ${sheet.title}`);
       await copiedSheet.loadHeaderRow();
-      expect(copiedSheet.headers).toEqual(sheet.headers);
+      expect(copiedSheet.headerValues).toEqual(sheet.headerValues);
       await copiedSheet.delete();
     });
   });

test/rows.test.js

@@ -165,4 +165,38 @@ describe('Row-based operations', () => {
       );
     });
   });
+
+  describe('header validation and cleanup', () => {
+    beforeAll(async () => {
+      sheet.loadCells('A1:E1');
+    });
+
+    it('allows empty headers', async () => {
+      await sheet.setHeaderRow(['', 'col1', '', 'col2']);
+      rows = await sheet.getRows();
+      expect(rows[0]['']).toBeUndefined();
+      expect(rows[0].col1).not.toBeUndefined();
+    });
+
+    it('trims each header', async () => {
+      await sheet.setHeaderRow([' col1 ', ' something with spaces ']);
+      rows = await sheet.getRows();
+      expect(rows[0].col1).not.toBeUndefined();
+      expect(rows[0]['something with spaces']).not.toBeUndefined();
+    });
+
+    it('throws an error if setting duplicate headers', async () => {
+      await expect(sheet.setHeaderRow(['col1', 'col1'])).rejects.toThrow();
+    });
+
+    it('throws an error if duplicate headers already exist', async () => {
+      await sheet.loadCells('A1:C1');
+      sheet.getCellByA1('A1').value = 'col1';
+      sheet.getCellByA1('B1').value = 'col1';
+      sheet.getCellByA1('C1').value = 'col2';
+      await sheet.saveUpdatedCells();
+      sheet.resetLocalCache(true); // forget the header values
+      await expect(sheet.getRows()).rejects.toThrow();
+    });
+  });
 });