Add default parameters to each border radius mixin (#31571)

* Add default parameters to each border radius mixin

* Add border radius changes to migration guide

Co-authored-by: Jeremy Jackson <[email protected]>

2 files changed, 9 insertions, 8 deletions

diff --git a/scss/mixins/_border-radius.scss b/scss/mixins/_border-radius.scss
index aee9bf3d3..3163fc0e7 100644
--- a/scss/mixins/_border-radius.scss
+++ b/scss/mixins/_border-radius.scss
@@ -23,53 +23,53 @@
   }
 }
 
-@mixin border-top-radius($radius) {
+@mixin border-top-radius($radius: $border-radius) {
   @if $enable-rounded {
     border-top-left-radius: valid-radius($radius);
     border-top-right-radius: valid-radius($radius);
   }
 }
 
-@mixin border-right-radius($radius) {
+@mixin border-right-radius($radius: $border-radius) {
   @if $enable-rounded {
     border-top-right-radius: valid-radius($radius);
     border-bottom-right-radius: valid-radius($radius);
   }
 }
 
-@mixin border-bottom-radius($radius) {
+@mixin border-bottom-radius($radius: $border-radius) {
   @if $enable-rounded {
     border-bottom-right-radius: valid-radius($radius);
     border-bottom-left-radius: valid-radius($radius);
   }
 }
 
-@mixin border-left-radius($radius) {
+@mixin border-left-radius($radius: $border-radius) {
   @if $enable-rounded {
     border-top-left-radius: valid-radius($radius);
     border-bottom-left-radius: valid-radius($radius);
   }
 }
 
-@mixin border-top-left-radius($radius) {
+@mixin border-top-left-radius($radius: $border-radius) {
   @if $enable-rounded {
     border-top-left-radius: valid-radius($radius);
   }
 }
 
-@mixin border-top-right-radius($radius) {
+@mixin border-top-right-radius($radius: $border-radius) {
   @if $enable-rounded {
     border-top-right-radius: valid-radius($radius);
   }
 }
 
-@mixin border-bottom-right-radius($radius) {
+@mixin border-bottom-right-radius($radius: $border-radius) {
   @if $enable-rounded {
     border-bottom-right-radius: valid-radius($radius);
   }
 }
 
-@mixin border-bottom-left-radius($radius) {
+@mixin border-bottom-left-radius($radius: $border-radius) {
   @if $enable-rounded {
     border-bottom-left-radius: valid-radius($radius);
   }
diff --git a/site/content/docs/5.0/migration.md b/site/content/docs/5.0/migration.md
index 4a4cddbcb..03657ea0f 100644
--- a/site/content/docs/5.0/migration.md
+++ b/site/content/docs/5.0/migration.md
@@ -111,6 +111,7 @@ Changes to our source Sass files and compiled CSS.
 - The `media-breakpoint-down()` uses the breakpoint itself instead of the next breakpoint. Use `media-breakpoint-down(lg)` instead of `media-breakpoint-down(md)` to target viewports smaller than the `lg` breakpoint.
 - The `media-breakpoint-between()` mixin's second parameter also uses the breakpoint itself instead of the next breakpoint. Use `media-between(sm, lg)` instead of `media-breakpoint-between(sm, md)` to target viewports between the `sm` and `lg` breakpoints.
 - The `box-shadow()` mixin now better supports `none` and `null` with multiple arguments. Now you can pass multiple arguements with either value, and get the expected output. [See #30394](https://github.com/twbs/bootstrap/pull/30394).
+- Each `border-radius()` mixin now has a default value. You can now call these mixins without specifying a border radius value and the `$border-radius` variable will be used. [See #31571](https://github.com/twbs/bootstrap/pull/31571)
 
 ### JavaScript