Sort uppercase before lowercase

Author: stormwarning

.changeset/famous-insects-matter.md

@@ -0,0 +1,5 @@
+---
+'eslint-plugin-import-sorting': minor
+---
+
+Explicitly set case sensitivity & sort uppercase before lowercase

src/rules/order.ts

@@ -51,7 +51,7 @@ export default createRule<unknown[], MessageId>({
 	create(context) {
 		let { settings, sourceCode } = context
 		let options: Options = {
-			ignoreCase: true,
+			ignoreCase: false,
 			newlinesBetween: 'always',
 			order: 'asc',
 			type: 'natural',

src/rules/specifier-order.ts

@@ -47,7 +47,7 @@ export default createRule<unknown[], MessageId>({
 		let { sourceCode } = context
 		let options: Options = {
 			ignoreAlias: true,
-			ignoreCase: true,
+			ignoreCase: false,
 			groupKind: 'mixed',
 			order: 'asc',
 			type: 'natural',

src/utils/compare.ts

@@ -57,7 +57,11 @@ function stripProtocol(name: string) {
 function compareString(first: string, second: string) {
 	if (first.startsWith('.') && !second.startsWith('.')) return 1
 	if (!first.startsWith('.') && second.startsWith('.')) return -1
-	return first.localeCompare(second, 'en', { numeric: true })
+	return first.localeCompare(second, 'en', {
+		caseFirst: 'upper',
+		numeric: true,
+		sensitivity: 'case',
+	})
 }
 
 function compareDotSegments(first: string, second: string) {

tests/rules/order.test.ts

@@ -58,6 +58,47 @@ describe('order', () => {
 			],
 		})
 
+		ruleTester.run('checks character case', orderRule, {
+			valid: [
+				{
+					name: 'without errors',
+					code: dedent`
+						import { a } from 'Arrow'
+						import { b } from 'arrow'
+						import { c } from 'Arrows'
+						import { d } from 'ArrowTurn'
+					`,
+				},
+			],
+			invalid: [
+				{
+					name: 'fixes import order',
+					code: dedent`
+						import { a } from 'Arrow'
+						import { d } from 'ArrowTurn'
+						import { c } from 'Arrows'
+						import { b } from 'arrow'
+					`,
+					output: dedent`
+						import { a } from 'Arrow'
+						import { b } from 'arrow'
+						import { c } from 'Arrows'
+						import { d } from 'ArrowTurn'
+					`,
+					errors: [
+						{
+							messageId: 'out-of-order',
+							data: { left: 'ArrowTurn', right: 'Arrows' },
+						},
+						{
+							messageId: 'out-of-order',
+							data: { left: 'Arrows', right: 'arrow' },
+						},
+					],
+				},
+			],
+		})
+
 		ruleTester.run('sorts imports into groups', orderRule, {
 			valid: [
 				{