PB-818: adding unit tests for adjust width

 - We also added some safeguards against division by 0, and corrected the DPI compensation constant name across the code where we forgot to do it.

src/api/__tests__/print.api.spec.js

@@ -2,6 +2,8 @@ import { expect } from 'chai'
 import { describe, it } from 'vitest'
 
 import { PrintLayout, PrintLayoutAttribute } from '@/api/print.api.js'
+import { PRINT_DPI_COMPENSATION } from '@/config/print.config'
+import { adjustWidth } from '@/utils/styleUtils'
 
 describe('Print API unit tests', () => {
     describe('PrintLayoutAttribute tests', () => {
@@ -61,5 +63,22 @@ describe('Print API unit tests', () => {
             )
             expect(scalesInMapAttr.scales).to.eql(scales)
         })
+        it('calculate the width correctly with the "adjustWidth" function', () => {
+            // invalid values should return 0
+            expect(adjustWidth(100, 'invalid value')).to.eql(0)
+            expect(adjustWidth(100, null)).to.eql(0)
+            expect(adjustWidth(100, undefined)).to.eql(0)
+            expect(adjustWidth(null, 254)).to.eql(0)
+            expect(adjustWidth(undefined, 254)).to.eql(0)
+            expect(adjustWidth('invalid value', 254)).to.eql(0)
+            // the dpi parameter should be a positive number
+            expect(adjustWidth(100, 0)).to.eql(0)
+            expect(adjustWidth(100, -15)).to.eql(0)
+            // checking with a slight margin for float rounding errors.
+            expect(adjustWidth(100, 254)).to.be.closeTo(
+                (100 * PRINT_DPI_COMPENSATION) / 254,
+                1 / 254
+            )
+        })
     })
 })

src/utils/styleUtils.js

@@ -1,7 +1,7 @@
 import { Circle, Fill, Stroke, Style } from 'ol/style'
 import CircleStyle from 'ol/style/Circle.js'
 
-import { PRINT_MAGIC_NUMBER } from '@/config/print.config'
+import { PRINT_DPI_COMPENSATION } from '@/config/print.config'
 import variables from '@/scss/variables-admin.module.scss'
 
 const { red, mocassin, mocassinToRed1, mocassinToRed2, malibu, black, white } = variables
@@ -159,9 +159,9 @@ export const highlightPointStyle = new Style({
 // Change a width according to the change of DPI (from the old geoadmin)
 // Originally introduced here https://github.com/geoadmin/mf-geoadmin3/pull/3280
 export function adjustWidth(width, dpi) {
-    if (!width || isNaN(width || isNaN(dpi) || dpi <= 0)) {
+    if (!width || isNaN(width) || !dpi || isNaN(dpi) || dpi <= 0) {
         return 0
     }
 
-    return (width * PRINT_MAGIC_NUMBER) / dpi
+    return (width * PRINT_DPI_COMPENSATION) / dpi
 }