Early exit if target function isn't present (scss-replace-duration and scss-replace-easing) (Shopify#7979)

The current migrations would inject a migration comment when
encountering any numeric operator in a style declaration.

This change adds an early exit if the target Sass function ins't present
in the declaration.

Author: sam-b-rose

.changeset/twenty-pumpkins-fry.md

@@ -0,0 +1,5 @@
+---
+'@shopify/polaris-migrator': patch
+---
+
+Early exit if target function isn't present for the scss-replace-duration and scss-replace-easing migrations

polaris-migrator/src/migrations/scss-replace-duration/scss-replace-duration.ts

@@ -7,6 +7,7 @@ import {
   createSassMigrator,
   setNodeValue,
   StopWalkingFunctionNodes,
+  hasSassFunction,
 } from '../../utilities/sass';
 import {isKeyOf} from '../../utilities/type-guards';
 
@@ -30,6 +31,8 @@ export default createSassMigrator(
       methods.walkDecls(root, (decl) => {
         const parsedValue = valueParser(decl.value);
 
+        if (!hasSassFunction(namespacedDuration, parsedValue)) return;
+
         parsedValue.walk((node) => {
           if (isNumericOperator(node)) {
             methods.report({

polaris-migrator/src/migrations/scss-replace-easing/scss-replace-easing.ts

@@ -7,6 +7,7 @@ import {
   createSassMigrator,
   setNodeValue,
   StopWalkingFunctionNodes,
+  hasSassFunction,
 } from '../../utilities/sass';
 import {isKeyOf} from '../../utilities/type-guards';
 
@@ -29,6 +30,8 @@ export default createSassMigrator(
       methods.walkDecls(root, (decl) => {
         const parsedValue = valueParser(decl.value);
 
+        if (!hasSassFunction(namespacedEasing, parsedValue)) return;
+
         parsedValue.walk((node) => {
           if (isNumericOperator(node)) {
             methods.report({