Add support for wrapping with newlines

src/calculateCellHeight.js

@@ -1,6 +1,5 @@
 import _ from 'lodash';
-import stringWidth from 'string-width';
-import wrapWord from './wrapWord';
+import wrapCell from './wrapCell';
 
 /**
  * @param {string} value
@@ -21,9 +20,5 @@ export default (value, columnWidth, useWrapWord = false) => {
     throw new Error('Column width must be greater than 0.');
   }
 
-  if (useWrapWord) {
-    return wrapWord(value, columnWidth).length;
-  }
-
-  return Math.ceil(stringWidth(value) / columnWidth);
+  return wrapCell(value, columnWidth, useWrapWord).length;
 };

src/mapDataUsingRowHeightIndex.js

@@ -1,6 +1,5 @@
 import _ from 'lodash';
-import wrapString from './wrapString';
-import wrapWord from './wrapWord';
+import wrapCell from './wrapCell';
 
 /**
  * @param {Array} unmappedRows
@@ -21,16 +20,10 @@ export default (unmappedRows, rowHeightIndex, config) => {
     //     [{cell index within a virtual row; index1}]
 
     cells.forEach((value, index1) => {
-      let chunkedValue;
+      const cellLines = wrapCell(value, config.columns[index1].width, config.columns[index1].wrapWord);
 
-      if (config.columns[index1].wrapWord) {
-        chunkedValue = wrapWord(value, config.columns[index1].width);
-      } else {
-        chunkedValue = wrapString(value, config.columns[index1].width);
-      }
-
-      chunkedValue.forEach((part, index2) => {
-        rowHeight[index2][index1] = part;
+      cellLines.forEach((cellLine, index2) => {
+        rowHeight[index2][index1] = cellLine;
       });
     });
 

src/wrapCell.js

@@ -0,0 +1,35 @@
+import wrapString from './wrapString';
+import wrapWord from './wrapWord';
+
+/**
+ * Wrap a single cell value into a list of lines
+ *
+ * Always wraps on newlines, for the remainder uses either word or string wrapping
+ * depending on user configuration.
+ *
+ * @param {string} cellValue
+ * @param {number} columnWidth
+ * @param {boolean} useWrapWord
+ * @returns {Array}
+ */
+export default (cellValue, columnWidth, useWrapWord) => {
+  // First split on literal newlines
+  const cellLines = cellValue.split('\n');
+
+  // Then iterate over the list and word-wrap every remaining line if necessary.
+  for (let lineNr = 0; lineNr < cellLines.length;) {
+    let lineChunks;
+
+    if (useWrapWord) {
+      lineChunks = wrapWord(cellLines[lineNr], columnWidth);
+    } else {
+      lineChunks = wrapString(cellLines[lineNr], columnWidth);
+    }
+
+    // Replace our original array element with whatever the wrapping returned
+    cellLines.splice(lineNr, 1, ...lineChunks);
+    lineNr += lineChunks.length;
+  }
+
+  return cellLines;
+};

test/calculateCellHeight.js

@@ -14,6 +14,12 @@ describe('calculateCellHeight', () => {
         }).to.throw(Error, 'Value must be a string.');
       });
     });
+    it('contains newlines', () => {
+      expect(calculateCellHeight('a\nb\nc', 10)).to.equal(3);
+    });
+    it('contains newlines and will be wrapped', () => {
+      expect(calculateCellHeight('aa\nbbb\nc', 2)).to.equal(4);
+    });
   });
   describe('context width', () => {
     context('is not an integer', () => {

test/mapDataUsingRowHeightIndex.js

@@ -66,6 +66,38 @@ describe('mapDataUsingRowHeightIndex', () => {
     });
   });
 
+  context('single cell contains newlines', () => {
+    it('maps data to multiple rows', () => {
+      const config = {
+        columns: {
+          0: {
+            width: 100
+          }
+        }
+      };
+
+      const rowSpanIndex = [
+        5
+      ];
+
+      const data = [
+        [
+          'aa\nbb\ncc\ndd\nee'
+        ]
+      ];
+
+      const mappedData = mapDataUsingRowHeightIndex(data, rowSpanIndex, config);
+
+      expect(mappedData).to.deep.equal([
+        ['aa'],
+        ['bb'],
+        ['cc'],
+        ['dd'],
+        ['ee']
+      ]);
+    });
+  });
+
   context('multiple cells spans multiple rows', () => {
     it('maps data to multiple rows', () => {
       const config = {