6 files changed, 91 insertions, 16 deletions
diff --git a/build/build-pages.js b/build/build-pages.js
index 911524d..6825be4 100644
--- a/build/build-pages.js
+++ b/build/build-pages.js
@@ -2,8 +2,8 @@
 
 'use strict'
 
-const fs = require('fs').promises
-const path = require('path')
+const fs = require('node:fs').promises
+const path = require('node:path')
 const picocolors = require('picocolors')
 
 const iconsDir = path.join(__dirname, '../icons/')
@@ -53,7 +53,7 @@ tags:
 
     const filesLength = files.length
 
-    console.log(picocolors.green('\nSuccess, %s page%s prepared!'), filesLength, filesLength !== 1 ? 's' : '')
+    console.log(picocolors.green('\nSuccess, %s page%s prepared!'), filesLength, filesLength === 1 ? '' : 's')
     console.timeEnd(timeLabel)
   } catch (error) {
     console.error(error)
diff --git a/build/build-svgs.js b/build/build-svgs.js
index c889ce5..ed868e6 100644
--- a/build/build-svgs.js
+++ b/build/build-svgs.js
@@ -2,9 +2,9 @@
 
 'use strict'
 
-const fs = require('fs').promises
-const path = require('path')
-const process = require('process')
+const fs = require('node:fs').promises
+const path = require('node:path')
+const process = require('node:process')
 const picocolors = require('picocolors')
 const { loadConfig, optimize } = require('svgo')
 
@@ -46,7 +46,7 @@ async function processFile(file, config) {
 
     const filesLength = files.length
 
-    console.log(picocolors.green('\nSuccess, prepared %s icon%s!'), filesLength, filesLength !== 1 ? 's' : '')
+    console.log(picocolors.green('\nSuccess, prepared %s icon%s!'), filesLength, filesLength === 1 ? '' : 's')
     console.timeEnd(timeLabel)
   } catch (error) {
     console.error(error)
diff --git a/build/check-icons.js b/build/check-icons.js
new file mode 100755
index 0000000..73f1a5b
--- /dev/null
+++ b/build/check-icons.js
@@ -0,0 +1,59 @@
+#!/usr/bin/env node
+
+'use strict'
+
+const fs = require('node:fs').promises
+const path = require('node:path')
+const process = require('node:process')
+const picocolors = require('picocolors')
+
+const fontJsonPath = path.join(__dirname, '../font/bootstrap-icons.json')
+const iconsDir = path.join(__dirname, '../icons/')
+
+;(async () => {
+  try {
+    const basename = path.basename(__filename)
+    const timeLabel = picocolors.cyan(`[${basename}] finished`)
+
+    console.log(picocolors.cyan(`[${basename}] started`))
+    console.time(timeLabel)
+
+    const fontJsonString = await fs.readFile(fontJsonPath, 'utf8')
+    const fontJson = JSON.parse(fontJsonString)
+    const svgFiles = await fs.readdir(iconsDir)
+
+    const jsonIconList = Object.keys(fontJson)
+    const svgIconList = svgFiles.map(svg => path.basename(svg, path.extname(svg)))
+
+    const onlyInJson = jsonIconList.filter(icon => !svgIconList.includes(icon))
+    const onlyInSvg = svgIconList.filter(icon => !jsonIconList.includes(icon))
+
+    if (onlyInJson.length === 0 || onlyInSvg === 0) {
+      console.log(picocolors.green('Success, found no differences!'))
+      console.timeEnd(timeLabel)
+
+      return
+    }
+
+    if (onlyInJson.length > 0) {
+      console.error(picocolors.red(`Found additional icons in ${fontJsonPath}:`))
+
+      for (const icon of onlyInJson) {
+        console.log(`  - ${picocolors.red(icon)}`)
+      }
+    }
+
+    if (onlyInSvg.length > 0) {
+      console.error(picocolors.red('Found additional icons in SVG files:'))
+
+      for (const icon of onlyInSvg) {
+        console.log(`  - ${picocolors.red(icon)}`)
+      }
+    }
+
+    process.exit(1)
+  } catch (error) {
+    console.error(error)
+    process.exit(1)
+  }
+})()
diff --git a/build/font/css.hbs b/build/font/css.hbs
index b6de062..6f2aa30 100644
--- a/build/font/css.hbs
+++ b/build/font/css.hbs
@@ -1,3 +1,9 @@
+/*!
+ * Bootstrap Icons (https://icons.getbootstrap.com/)
+ * Copyright 2019-2023 The Bootstrap Authors
+ * Licensed under MIT (https://github.com/twbs/icons/blob/main/LICENSE.md)
+ */
+
 @font-face {
   font-display: block;
   font-family: "{{ name }}";
diff --git a/build/font/scss.hbs b/build/font/scss.hbs
index ce0617d..710b45c 100644
--- a/build/font/scss.hbs
+++ b/build/font/scss.hbs
@@ -1,9 +1,15 @@
+/*!
+ * Bootstrap Icons (https://icons.getbootstrap.com/)
+ * Copyright 2019-2023 The Bootstrap Authors
+ * Licensed under MIT (https://github.com/twbs/icons/blob/main/LICENSE.md)
+ */
+
 ${{ name }}-font: "{{ name }}" !default;
 ${{ name }}-font-dir: "{{ fontsUrl }}" !default;
-${{ name }}-font-file: #{${{ name }}-font-dir}/#{${{ name }}-font} !default;
+${{ name }}-font-file: "#{${{ name }}-font-dir}/#{${{ name }}-font}" !default;
 ${{ name }}-font-hash: "24e3eb84d0bcaf83d77f904c78ac1f47" !default;
 ${{ name }}-font-src: url("#{${{ name }}-font-file}.woff2?#{${{ name }}-font-hash}") format("woff2"),
-                      url("#{${{ name }}-font-file}.woff?#{${{ name }}-font-hash}") format("woff") !default;
+                           url("#{${{ name }}-font-file}.woff?#{${{ name }}-font-hash}") format("woff") !default;
 
 @font-face {
   font-display: block;
@@ -32,6 +38,6 @@ ${{ name }}-map: (
 {{/ each }}
 );
 
-{{# each codepoints }}
-.{{ ../prefix }}-{{ @key }}::before { content: map-get(${{ ../name }}-map, "{{ @key }}"); }
-{{/ each }}
+@each $icon, $codepoint in ${{ name }}-map {
+  .{{ prefix }}-#{$icon}::before { content: $codepoint; }
+}
diff --git a/build/vnu-jar.js b/build/vnu-jar.js
index 6885015..c87d518 100644
--- a/build/vnu-jar.js
+++ b/build/vnu-jar.js
@@ -2,22 +2,24 @@
 
 /*!
  * Script to run vnu-jar if Java is available.
- * Copyright 2017-2022 The Bootstrap Authors
- * Copyright 2017-2022 Twitter, Inc.
+ * Copyright 2017-2023 The Bootstrap Authors
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/main/LICENSE)
  */
 
 'use strict'
 
-const { execFile, spawn } = require('child_process')
+const { execFile, spawn } = require('node:child_process')
 const vnu = require('vnu-jar')
 
 execFile('java', ['-version'], (error, stdout, stderr) => {
   if (error) {
-    console.error('Skipping vnu-jar test; Java is missing.')
+    console.error('Skipping vnu-jar test; Java is probably missing.')
+    console.error(error)
     return
   }
 
+  console.log('Running vnu-jar validation...')
+
   const is32bitJava = !/64-Bit/.test(stderr)
 
   // vnu-jar accepts multiple ignores joined with a `|`.
@@ -40,6 +42,8 @@ execFile('java', ['-version'], (error, stdout, stderr) => {
     args.splice(0, 0, '-Xss512k')
   }
 
+  console.log(`command used: java ${args.join(' ')}`)
+
   return spawn('java', args, {
     shell: true,
     stdio: 'inherit'