build: Update @mll-lab/eslint-plugin to ^1.4.0 (#56)

* Update @mll-lab/eslint-plugin to ^1.4.0

Apply new prefer-loose-nullish-equality rule.

Co-Authored-By: Claude <noreply@anthropic.com>

* Fix test: preserve null/undefined distinction in errorMessage

The errorMessage function intentionally treats null and undefined
differently (null returns "null" via JSON.stringify, undefined returns
"undefined" string). Added eslint-disable comment to preserve this.

Co-Authored-By: Claude <noreply@anthropic.com>

* turn around

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: spawnia

package.json

@@ -52,7 +52,7 @@
     "@babel/preset-env": "^7.13.0",
     "@babel/runtime": "^7.13.6",
     "@mll-lab/eslint-config": "^3.1.0",
-    "@mll-lab/eslint-plugin": "^1.3.4",
+    "@mll-lab/eslint-plugin": "^1.4.0",
     "@mll-lab/prettier-config": "^1.0.0",
     "@mll-lab/tsconfig": "^1.1.0",
     "@rollup/plugin-babel": "^5.3.0",

src/error.ts

@@ -7,6 +7,7 @@
 export function errorMessage(error: unknown): string {
   const message = hasMessage(error) ? error.message : error;
 
+  // eslint-disable-next-line @mll-lab/prefer-loose-nullish-equality -- intentionally distinguish null and undefined
   if (message === undefined) {
     return 'undefined';
   }
@@ -15,5 +16,5 @@ export function errorMessage(error: unknown): string {
 }
 
 function hasMessage(error: unknown): error is { message: unknown } {
-  return typeof error === 'object' && error !== null && 'message' in error;
+  return error != null && typeof error === 'object' && 'message' in error;
 }

src/germanNumber.ts

@@ -35,7 +35,7 @@ export function formatGermanNumber(
 export function parseGermanNumber(
   value: string | null | undefined,
 ): number | null {
-  if (value === null || value === undefined) {
+  if (value == null) {
     return null;
   }
 

src/number.ts

@@ -16,7 +16,7 @@ export function firstDecimalDigit(number: number): number {
   const regExp = /\d*\.(\d)/;
   const regExpMatchArray = number.toString().match(regExp);
 
-  if (regExpMatchArray === null) {
+  if (regExpMatchArray == null) {
     throw new Error(`Invalid number for regex matching: ${number}`);
   }
 

yarn.lock

@@ -1829,14 +1829,14 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@mll-lab/eslint-plugin@npm:^1.3.4":
-  version: 1.3.4
-  resolution: "@mll-lab/eslint-plugin@npm:1.3.4"
+"@mll-lab/eslint-plugin@npm:^1.4.0":
+  version: 1.4.0
+  resolution: "@mll-lab/eslint-plugin@npm:1.4.0"
   dependencies:
     "@typescript-eslint/experimental-utils": "npm:^5.62"
   peerDependencies:
     eslint: ^8.8.0
-  checksum: 10c0/228442c1ddaccf094e0fd4e2d7116fbbac29977d4ba12d7c4b435453f730a4a93c66c428f9df8afacb26bcd5e728ea51404a556b1f9bf4053243e1d68d3cbcdd
+  checksum: 10c0/695c1f8720a89418222c63f527e03a898eca8d325549685b40b52fe31ddd252517501aebf76effca003f7acada303bc6ca316845c16837b53800c89f57d44cc9
   languageName: node
   linkType: hard
 
@@ -1850,7 +1850,7 @@ __metadata:
     "@babel/preset-env": "npm:^7.13.0"
     "@babel/runtime": "npm:^7.13.6"
     "@mll-lab/eslint-config": "npm:^3.1.0"
-    "@mll-lab/eslint-plugin": "npm:^1.3.4"
+    "@mll-lab/eslint-plugin": "npm:^1.4.0"
     "@mll-lab/prettier-config": "npm:^1.0.0"
     "@mll-lab/tsconfig": "npm:^1.1.0"
     "@rollup/plugin-babel": "npm:^5.3.0"