From bbee3c44e9236ca823c1c85ebd03087f78d29656 Mon Sep 17 00:00:00 2001
From: Jen Downs <hello@jendowns.com>
Date: Mon, 23 Dec 2019 16:29:19 -0600
Subject: [PATCH 1/2] fix(styles): add error handling for rem & em sass
 functions (#4931)

---
 packages/components/src/globals/scss/_typography.scss | 10 ++++++++++
 packages/layout/scss/_convert.scss                    | 10 ++++++++++
 2 files changed, 20 insertions(+)

diff --git a/packages/components/src/globals/scss/_typography.scss b/packages/components/src/globals/scss/_typography.scss
index ad3932a18345..a1bcf9ea28d3 100644
--- a/packages/components/src/globals/scss/_typography.scss
+++ b/packages/components/src/globals/scss/_typography.scss
@@ -22,6 +22,11 @@ $base-font-size: 16px !default;
 /// @group global-typography
 /// @deprecated (For v10) Use `carbon--rem()`
 @function rem($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $base-font-size) * 1rem;
 }
 
@@ -33,6 +38,11 @@ $base-font-size: 16px !default;
 /// @group global-typography
 /// @deprecated (For v10) Use `carbon--em()`
 @function em($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $base-font-size) * 1em;
 }
 
diff --git a/packages/layout/scss/_convert.scss b/packages/layout/scss/_convert.scss
index 339fc78e5257..7c5f5d98a69d 100644
--- a/packages/layout/scss/_convert.scss
+++ b/packages/layout/scss/_convert.scss
@@ -17,6 +17,11 @@ $carbon--base-font-size: 16px !default;
 /// @access public
 /// @group @carbon/layout
 @function carbon--rem($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $carbon--base-font-size) * 1rem;
 }
 
@@ -26,5 +31,10 @@ $carbon--base-font-size: 16px !default;
 /// @access public
 /// @group @carbon/layout
 @function carbon--em($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $carbon--base-font-size) * 1em;
 }

From 6c1042e05fb93fc604757b355a1f5574010e2788 Mon Sep 17 00:00:00 2001
From: carbon-bot <carbon@us.ibm.com>
Date: Mon, 23 Dec 2019 22:40:37 +0000
Subject: [PATCH 2/2] chore(project): sync generated files

---
 packages/components/docs/sass.md | 10 ++++++++++
 packages/elements/docs/sass.md   | 10 ++++++++++
 packages/layout/docs/sass.md     | 10 ++++++++++
 3 files changed, 30 insertions(+)

diff --git a/packages/components/docs/sass.md b/packages/components/docs/sass.md
index e3a31a81d2cd..767c399c5729 100644
--- a/packages/components/docs/sass.md
+++ b/packages/components/docs/sass.md
@@ -2550,6 +2550,11 @@ Convert a given px unit to a rem unit
 
 ```scss
 @function carbon--rem($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $carbon--base-font-size) * 1rem;
 }
 ```
@@ -2579,6 +2584,11 @@ Convert a given px unit to a em unit
 
 ```scss
 @function carbon--em($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $carbon--base-font-size) * 1em;
 }
 ```
diff --git a/packages/elements/docs/sass.md b/packages/elements/docs/sass.md
index 11c79e41efa3..aae30c75a745 100644
--- a/packages/elements/docs/sass.md
+++ b/packages/elements/docs/sass.md
@@ -2326,6 +2326,11 @@ Convert a given px unit to a rem unit
 
 ```scss
 @function carbon--rem($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $carbon--base-font-size) * 1rem;
 }
 ```
@@ -2354,6 +2359,11 @@ Convert a given px unit to a em unit
 
 ```scss
 @function carbon--em($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $carbon--base-font-size) * 1em;
 }
 ```
diff --git a/packages/layout/docs/sass.md b/packages/layout/docs/sass.md
index 68fa9d47bfc1..79e92eae719d 100644
--- a/packages/layout/docs/sass.md
+++ b/packages/layout/docs/sass.md
@@ -733,6 +733,11 @@ Convert a given px unit to a rem unit
 
 ```scss
 @function carbon--rem($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $carbon--base-font-size) * 1rem;
 }
 ```
@@ -761,6 +766,11 @@ Convert a given px unit to a em unit
 
 ```scss
 @function carbon--em($px) {
+  @if unit($px) != 'px' {
+    // TODO: update to @error in v11
+    @warn "Expected argument $px to be of type `px`, instead received: `#{unit($px)}`";
+  }
+
   @return ($px / $carbon--base-font-size) * 1em;
 }
 ```