feat: added prettier as formatter

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_style = space
+indent_size = 2
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.{yml,yaml}]
+indent_size = 2

.eslintrc.js

@@ -3,13 +3,9 @@ module.exports = {
     commonjs: true,
     node: true,
   },
-  extends: ['@parcellab/eslint-config/base'],
+  extends: ['@parcellab/eslint-config/base', 'prettier'],
   rules: {
-    'comma-dangle': ['error', 'always-multiline'],
     'prefer-const': 'error',
-    'quote-props': ['error', 'consistent-as-needed'],
-    'quotes': ['error', 'single'],
-    'semi': ['error', 'always'],
     'unicorn/prefer-module': 'off',
   },
 };

.github/workflows/test.yml

@@ -21,5 +21,6 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm ci
+      - run: npm run format:check
       - run: npm run build --if-present
       - run: npm test

.prettierignore

@@ -0,0 +1,7 @@
+node_modules
+package-lock.json
+
+# Generated/large data files: keep existing formatting to avoid noisy diffs.
+country/**/*.json
+regionNames/**/*.json
+regions/**/*.json

.prettierrc.json

@@ -0,0 +1,15 @@
+{
+  "singleQuote": true,
+  "semi": true,
+  "trailingComma": "all",
+  "quoteProps": "consistent",
+  "printWidth": 100,
+  "overrides": [
+    {
+      "files": ["*.yml", "*.yaml"],
+      "options": {
+        "singleQuote": false
+      }
+    }
+  ]
+}

DATA_REQUIREMENTS.md

@@ -1,18 +1,23 @@
 # Country Data Requirements
+
 Guide for adding a new country to the static Region Identifier dataset. Each supported country needs three JSON files plus a small code change.
 
 ## 1) Country config – `country/ISO3.json`
+
 - Keys:
   - `zipCodeFormat`: `"numeric"` or `"alpha"`.
   - `zipCodeLength`: integer, required for numeric formats to pad/compare values (USA=5, AUS=4, DEU=5, etc.). Omit for alpha formats (CAN/GBR/NLD).
 - Example:
+
 ```json
 { "zipCodeFormat": "numeric", "zipCodeLength": 5 }
 ```
 
 ## 2) Region names – `regionNames/ISO3.json`
+
 - Plain object mapping ISO 3166-2 region codes (same codes used in `regions/*.json`) to display names in English.
 - Example (`regionNames/AUS.json`):
+
 ```json
 {
   "AU-NSW": "New South Wales",
@@ -21,11 +26,15 @@ Guide for adding a new country to the static Region Identifier dataset. Each sup
 ```
 
 ## 3) Region mappings – `regions/ISO3.json`
+
 Array of objects that map postal codes to ISO 3166-2 region codes. Formats already used in the repo:
+
 - **Numeric intervals** (inclusive): objects with `low`, `high`, `region`. Values can be numbers or numeric strings if leading zeros matter. Example (`regions/AUS.json`):
+
 ```json
 { "region": "AU-NSW", "low": 1000, "high": 1999 }
 ```
+
 - **Explicit codes**: objects with `low`, `region`, no `high`. Every postal code (or prefix) must be listed. Use strings to preserve zeros. Examples:
   - Belgium lists every 4-digit code (`regions/BEL.json`).
   - Spain lists 5-digit codes as strings (`regions/ESP.json`).
@@ -34,20 +43,24 @@ Array of objects that map postal codes to ISO 3166-2 region codes. Formats alrea
 - **Discrete lists**: objects with `region` and `list` (array of codes). Numeric countries store numbers; matching uses `zipCodeLength` to pad leading zeros before comparison. Examples: USA (`list` of 5-digit numbers), RUS (per-region lists).
 
 Additional format notes:
+
 - Files can mix formats if needed. Order matters because the lookup stops at the first match.
 - Intervals and lists are treated as inclusive ranges; for alpha codes only exact equality is used.
 - Keep codes as strings when leading zeros are significant.
 
 ## 4) Code wiring
+
 - Add the ISO3 code to `availableCountries` in `lib/region.js`; otherwise the static data is ignored and Google is used.
 - If the country needs custom postal-code normalization, extend `validateZipCode` (see existing cases for GBR, CAN, NLD, MEX).
 
 ## 5) Testing
+
 - Add test cases to `test/tests.js` under `countriesPostalCodes`: include the country ISO/name, a representative zip, expected region code, and set `usingGoogle: false`.
 - Run `npm test` to execute the Node.js test runner.
 - Optional: verify pretty-name lookups via `getNameFromCountryAndRegion` using the `regionNames` file.
 
 ## 6) Data quality checklist
+
 - Region codes must be valid ISO 3166-2 for the country.
 - `regionNames` should be English and cover every region code present in `regions/ISO3.json`.
 - Postal-code coverage should include territories and edge prefixes (e.g., US territories, Canadian northern prefixes).

README.md

@@ -2,12 +2,14 @@
 
 Utility module that provides an easy way to identify the region of the country depending on the postal code, brings a set of determined regions for some of the countries and if it doesn't find a match uses google geolocation API to get the region.
 
-*Relevant links:*
-* https://en.wikipedia.org/wiki/ISO_3166-2 — codes used for all the regions can be found here
-* https://en.wikipedia.org/wiki/Category:Postal_codes_by_country - explanations of postal code structure per country
-* https://download.geonames.org/export/zip/ - all the Geoname files for download (see below)
+_Relevant links:_
+
+- https://en.wikipedia.org/wiki/ISO_3166-2 — codes used for all the regions can be found here
+- https://en.wikipedia.org/wiki/Category:Postal_codes_by_country - explanations of postal code structure per country
+- https://download.geonames.org/export/zip/ - all the Geoname files for download (see below)
 
 #### Predefined Regions
+
 - AUS
 - AUT
 - BRA
@@ -39,22 +41,27 @@ Utility module that provides an easy way to identify the region of the country d
 - USA
 
 ## Test
+
 ```sh
 $ npm test
 ```
 
 ### License
+
 This module was built using adapted information from http://download.geonames.org/ that's registered under the **CC BY 3.0** as well as this module.
 Link to more information about **CC BY 3.0** http://creativecommons.org/licenses/by/3.0/.
 
 ## Usage
 
 #### Basic:
+
 ```javascript
 const { RegionIdentifier } = requrie('regionIdentifier');
 const identifier = new RegionIdentifier('<GOOGLE API KEY>');
 ```
+
 #### Get region:
+
 ```javascript
 //Using country name
 identifier.get('Deutschland', '6578')

lib/region.js

@@ -172,19 +172,13 @@ function getRegionByZipCodeOnStaticFiles(countryIso, zip) {
       (regionMapping.list.includes(parseInt(zip)) ||
         (countryConfig.zipCodeFormat === 'numeric'
           ? regionMapping.list.some((l) =>
-              zip.startsWith(
-                String(l).padStart(countryConfig.zipCodeLength, '0'),
-              ),
+              zip.startsWith(String(l).padStart(countryConfig.zipCodeLength, '0')),
             )
           : false))
     ) {
       return regionMapping.region;
-    } else if (!regionMapping.high && zip === regionMapping.low)
-      return regionMapping.region;
-    else if (
-      parseInt(zip) >= regionMapping.low &&
-      parseInt(zip) <= regionMapping.high
-    )
+    } else if (!regionMapping.high && zip === regionMapping.low) return regionMapping.region;
+    else if (parseInt(zip) >= regionMapping.low && parseInt(zip) <= regionMapping.high)
       return regionMapping.region;
   }
 }
@@ -293,34 +287,30 @@ class RegionIdentifier {
     let response;
 
     try {
-      response = await axios.get(
-        googleLink.replace('####', encodeURIComponent(param)),
-      );
+      response = await axios.get(googleLink.replace('####', encodeURIComponent(param)));
     } catch (err) {
       throw new GoogleMapsAPIError('Google Maps API request failed: ' + JSON.stringify(err));
     }
 
-      if (!response?.data) {
-        return null;
-      }
+    if (!response?.data) {
+      return null;
+    }
 
-      if (response.data?.results?.length <= 0) {
-        return null;
-      }
+    if (response.data?.results?.length <= 0) {
+      return null;
+    }
 
-      // find country inside of the nested array
-      const region = response.data.results[0].address_components.find((component) => {
-        const typeFound = component.types.find(
-          (type) => type === 'administrative_area_level_1',
-        );
-        return typeFound && typeFound.length > 0;
-      });
+    // find country inside of the nested array
+    const region = response.data.results[0].address_components.find((component) => {
+      const typeFound = component.types.find((type) => type === 'administrative_area_level_1');
+      return typeFound && typeFound.length > 0;
+    });
 
-      if (!region) {
-        throw new GoogleMapsAPIError('NOT FOUND');
-      }
+    if (!region) {
+      throw new GoogleMapsAPIError('NOT FOUND');
+    }
 
-      return `${countryIso.alpha2}-${cleanAndCatchFaultyRegionName(region)}`;
+    return `${countryIso.alpha2}-${cleanAndCatchFaultyRegionName(region)}`;
   }
 }
 

package.json

@@ -19,7 +19,9 @@
   "homepage": "https://github.com/parcelLab/regionIdentifier",
   "scripts": {
     "test": "node --test test/tests.js",
-    "lint": "eslint ."
+    "lint": "eslint .",
+    "format": "prettier --write .",
+    "format:check": "prettier --check ."
   },
   "engines": {
     "node": ">=24.0.0"
@@ -30,8 +32,10 @@
   },
   "devDependencies": {
     "@parcellab/eslint-config": "^0.5.5",
+    "eslint-config-prettier": "^10.1.8",
     "eslint-plugin-import": "^2.32.0",
-    "eslint-plugin-promise": "^7.3.0"
+    "eslint-plugin-promise": "^7.3.0",
+    "prettier": "^3.9.4"
   },
   "overrides": {
     "eslint-plugin-unicorn": "47.0.0",

test/resolve.js

@@ -18,7 +18,7 @@ identifier
   .catch((err) => {
     console.error(err);
 
-    if(err instanceof GoogleMapsAPIError) {
+    if (err instanceof GoogleMapsAPIError) {
       console.error('Google Maps API error');
     }
   });