Simplify font family settings

CHANGELOG.md

@@ -265,6 +265,18 @@ If you need to maintain the existing behaviour, you can set the value to an empt
 
 This change was introduced in [pull request #3773: Omit the value attribute from select options with no value](https://github.com/alphagov/govuk-frontend/pull/3773).
 
+### Removal of font family Sass variables
+
+The following Sass variables have been removed:
+
+- `$govuk-font-family-gds-transport`
+- `$govuk-font-family-nta`
+- `$govuk-font-family-nta-tabular`
+
+If you were using `$govuk-font-family-gds-transport` to set the font on an element we recommend using [the `govuk-font` mixin](https://frontend.design-system.service.gov.uk/sass-api-reference/#govuk-font) instead.
+
+This change was introduced in [pull request #3949: Simplify font family settings](https://github.com/alphagov/govuk-frontend/pull/3949).
+
 ### Suggested changes
 
 #### Update the Pagination component's default `aria-label`

packages/govuk-frontend/src/govuk/settings/_all.scss

@@ -15,7 +15,6 @@
 @import "spacing";
 @import "measurements";
 
-@import "typography-font-families";
 @import "typography-font";
 @import "typography-responsive";
 

packages/govuk-frontend/src/govuk/settings/_typography-font.scss

@@ -1,5 +1,3 @@
-@import "typography-font-families";
-
 ////
 /// @group settings/typography
 ////
@@ -13,7 +11,7 @@
 /// @type List
 /// @access public
 
-$govuk-font-family: $govuk-font-family-gds-transport !default;
+$govuk-font-family: "GDS Transport", arial, sans-serif !default;
 
 /// Font families to use for print media
 ///
@@ -27,15 +25,13 @@ $govuk-font-family-print: sans-serif !default;
 
 /// Include the default @font-face declarations
 ///
-/// If you have set $govuk-font-family to something other than
-/// `$govuk-font-family-gds-transport` this option is disabled by default.
+/// Defaults to true if "GDS Transport" appears in the $govuk-font-family
+/// setting.
 ///
 /// @type Boolean
 /// @access public
 
-$govuk-include-default-font-face: (
-  $govuk-font-family == $govuk-font-family-gds-transport
-) !default;
+$govuk-include-default-font-face: if(index($govuk-font-family, "GDS Transport"), true, false) !default;
 
 // =========================================================
 // Font weights

packages/govuk-frontend/src/govuk/settings/typography.test.js

@@ -0,0 +1,44 @@
+const { compileSassString } = require('govuk-frontend-helpers/tests')
+
+describe('$govuk-include-default-font-face', () => {
+  it('is true if $govuk-font-family is default', async () => {
+    const sass = `
+      @import "settings/typography-font";
+      :root {
+        --result: #{$govuk-include-default-font-face}
+      }
+    `
+
+    await expect(compileSassString(sass)).resolves.toMatchObject({
+      css: expect.stringContaining('--result: true')
+    })
+  })
+
+  it('is true if $govuk-font-family includes GDS Transport', async () => {
+    const sass = `
+      $govuk-font-family: "GDS Transport", "Comic Sans MS", "Comic Sans", cursive;
+      @import "settings/typography-font";
+      :root {
+        --result: #{$govuk-include-default-font-face}
+      }
+    `
+
+    await expect(compileSassString(sass)).resolves.toMatchObject({
+      css: expect.stringContaining('--result: true')
+    })
+  })
+
+  it('is false if $govuk-font-family does not include GDS Transport', async () => {
+    const sass = `
+      $govuk-font-family: "Comic Sans MS", "Comic Sans", cursive;
+      @import "settings/typography-font";
+      :root {
+        --result: #{$govuk-include-default-font-face}
+      }
+    `
+
+    await expect(compileSassString(sass)).resolves.toMatchObject({
+      css: expect.stringContaining('--result: false')
+    })
+  })
+})