chore: use recommended restrict-plus-operands (#369)

17 files changed, 114 insertions, 185 deletions

diff --git a/.eslintrc.js b/.eslintrc.js
index ab862365..33042eeb 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -41,7 +41,6 @@ module.exports = defineConfig({
     '@typescript-eslint/no-unsafe-call': 'off',
     '@typescript-eslint/no-unsafe-member-access': 'off',
     '@typescript-eslint/no-unsafe-return': 'warn',
-    '@typescript-eslint/restrict-plus-operands': 'warn',
     '@typescript-eslint/restrict-template-expressions': [
       'error',
       {
diff --git a/scripts/apidoc.ts b/scripts/apidoc.ts
index 3d972c95..f07e5e06 100644
--- a/scripts/apidoc.ts
+++ b/scripts/apidoc.ts
@@ -232,7 +232,7 @@ async function build(): Promise<void> {
           .map((tag) => tag.text.trimEnd()) || [];
 
       if (examples.length !== 0) {
-        console.log('Example-Length: ' + examples);
+        console.log('Example-Length:', examples);
         content += examples.join('\n') + '\n';
       }
 
diff --git a/src/commerce.ts b/src/commerce.ts
index 61a5f5a1..1d6ac91d 100644
--- a/src/commerce.ts
+++ b/src/commerce.ts
@@ -64,7 +64,7 @@ export class Commerce {
     symbol: string = ''
   ): string {
     if (min < 0 || max < 0) {
-      return symbol + 0.0;
+      return `${symbol}${0.0}`;
     }
 
     const randValue = this.faker.datatype.number({ max: max, min: min });
diff --git a/src/finance.ts b/src/finance.ts
index 2d00570a..719d1198 100644
--- a/src/finance.ts
+++ b/src/finance.ts
@@ -64,7 +64,7 @@ export class Finance {
       sum += Number(routingNumber[i + 2]) || 0;
     }
 
-    return routingNumber + (Math.ceil(sum / 10) * 10 - sum);
+    return `${routingNumber}${Math.ceil(sum / 10) * 10 - sum}`;
   }
 
   /**
@@ -293,7 +293,12 @@ export class Finance {
    * @method faker.finance.iban
    */
   iban(formatted: boolean = false, countryCode: string): string {
-    let ibanFormat;
+    let ibanFormat: {
+      bban: Array<{ type: string; count: number }>;
+      country: string;
+      total?: number;
+      format?: string;
+    };
     if (countryCode) {
       const findFormat = (currentFormat) =>
         currentFormat.country === countryCode;
@@ -341,12 +346,12 @@ export class Finance {
     let checksum: string | number =
       98 -
       this.ibanLib.mod97(
-        this.ibanLib.toDigitString(s + ibanFormat.country + '00')
+        this.ibanLib.toDigitString(`${s}${ibanFormat.country}00`)
       );
     if (checksum < 10) {
-      checksum = '0' + checksum;
+      checksum = `0${checksum}`;
     }
-    const iban = ibanFormat.country + checksum + s;
+    const iban = `${ibanFormat.country}${checksum}${s}`;
     return formatted ? iban.match(/.{1,4}/g).join(' ') : iban;
   }
 
diff --git a/src/image.ts b/src/image.ts
index 00e94114..1a74f26e 100644
--- a/src/image.ts
+++ b/src/image.ts
@@ -87,13 +87,13 @@ export class Image {
     if (typeof https !== 'undefined' && https === true) {
       protocol = 'https://';
     }
-    let url = protocol + 'placeimg.com/' + width + '/' + height;
+    let url = `${protocol}placeimg.com/${width}/${height}`;
     if (typeof category !== 'undefined') {
       url += '/' + category;
     }
 
     if (randomize) {
-      url += '?' + this.faker.datatype.number();
+      url += `?${this.faker.datatype.number()}`;
     }
 
     return url;
@@ -264,22 +264,11 @@ export class Image {
    * @param color
    */
   dataUri(width?: number, height?: number, color: string = 'grey'): string {
-    const svgString =
-      '<svg xmlns="http://www.w3.org/2000/svg" version="1.1" baseProfile="full" width="' +
-      width +
-      '" height="' +
-      height +
-      '"><rect width="100%" height="100%" fill="' +
-      color +
-      '"/><text x="' +
-      width / 2 +
-      '" y="' +
-      height / 2 +
-      '" font-size="20" alignment-baseline="middle" text-anchor="middle" fill="white">' +
-      width +
-      'x' +
-      height +
-      '</text></svg>';
+    const svgString = `<svg xmlns="http://www.w3.org/2000/svg" version="1.1" baseProfile="full" width="${width}" height="${height}"><rect width="100%" height="100%" fill="${color}"/><text x="${
+      width / 2
+    }" y="${
+      height / 2
+    }" font-size="20" alignment-baseline="middle" text-anchor="middle" fill="white">${width}x${height}</text></svg>`;
     const rawPrefix = 'data:image/svg+xml;charset=UTF-8,';
     return rawPrefix + encodeURIComponent(svgString);
   }
diff --git a/src/image_providers/lorempicsum.ts b/src/image_providers/lorempicsum.ts
index 32c52867..635ab9e6 100644
--- a/src/image_providers/lorempicsum.ts
+++ b/src/image_providers/lorempicsum.ts
@@ -108,10 +108,10 @@ export class LoremPicsum {
       url += '/seed/' + seed;
     }
 
-    url += '/' + width + '/' + height;
+    url += `/${width}/${height}`;
 
     if (grayscale && blur) {
-      return url + '?grayscale' + '&blur=' + blur;
+      return `${url}?grayscale&blur=${blur}`;
     }
 
     if (grayscale) {
@@ -119,7 +119,7 @@ export class LoremPicsum {
     }
 
     if (blur) {
-      return url + '?blur=' + blur;
+      return `${url}?blur=${blur}`;
     }
 
     return url;
diff --git a/src/image_providers/lorempixel.ts b/src/image_providers/lorempixel.ts
index d152cd6e..045da3f2 100644
--- a/src/image_providers/lorempixel.ts
+++ b/src/image_providers/lorempixel.ts
@@ -61,13 +61,13 @@ export class Lorempixel {
     width ||= 640;
     height ||= 480;
 
-    let url = 'https://lorempixel.com/' + width + '/' + height;
+    let url = `https://lorempixel.com/${width}/${height}`;
     if (typeof category !== 'undefined') {
       url += '/' + category;
     }
 
     if (randomize) {
-      url += '?' + this.faker.datatype.number();
+      url += `?${this.faker.datatype.number()}`;
     }
 
     return url;
diff --git a/src/image_providers/unsplash.ts b/src/image_providers/unsplash.ts
index 1d358345..580a3d96 100644
--- a/src/image_providers/unsplash.ts
+++ b/src/image_providers/unsplash.ts
@@ -58,7 +58,7 @@ export class Unsplash {
       url += '/category/' + category;
     }
 
-    url += '/' + width + 'x' + height;
+    url += `/${width}x${height}`;
 
     if (typeof keyword !== 'undefined') {
       const keywordFormat = new RegExp(
diff --git a/src/internet.ts b/src/internet.ts
index b26654d1..2c663d58 100644
--- a/src/internet.ts
+++ b/src/internet.ts
@@ -185,11 +185,9 @@ export class Internet {
    * @method faker.internet.avatar
    */
   avatar(): string {
-    return (
-      'https://cloudflare-ipfs.com/ipfs/Qmd3W5DuhgHirLHGVixi6V76LhCkZUz6pnFt5AJBiyvHye/avatar/' +
-      this.faker.datatype.number(1249) +
-      '.jpg'
-    );
+    return `https://cloudflare-ipfs.com/ipfs/Qmd3W5DuhgHirLHGVixi6V76LhCkZUz6pnFt5AJBiyvHye/avatar/${this.faker.datatype.number(
+      1249
+    )}.jpg`;
   }
 
   /**
@@ -240,18 +238,17 @@ export class Internet {
     lastName ||= this.faker.name.lastName();
     switch (this.faker.datatype.number(2)) {
       case 0:
-        result = firstName + this.faker.datatype.number(99);
+        result = `${firstName}${this.faker.datatype.number(99)}`;
         break;
       case 1:
         result =
           firstName + this.faker.random.arrayElement(['.', '_']) + lastName;
         break;
       case 2:
-        result =
-          firstName +
-          this.faker.random.arrayElement(['.', '_']) +
-          lastName +
-          this.faker.datatype.number(99);
+        result = `${firstName}${this.faker.random.arrayElement([
+          '.',
+          '_',
+        ])}${lastName}${this.faker.datatype.number(99)}`;
         break;
     }
     result = result.toString().replace(/'/g, '');
diff --git a/src/lorem.ts b/src/lorem.ts
index 5583b510..9368ec01 100644
--- a/src/lorem.ts
+++ b/src/lorem.ts
@@ -149,7 +149,7 @@ export class Lorem {
       'lorem.lines',
     ];
     const randomLoremMethod = this.faker.random.arrayElement(loremMethods);
-    return this.faker.fake('{{' + randomLoremMethod + '}}');
+    return this.faker.fake(`{{${randomLoremMethod}}}`);
   }
 
   /**
diff --git a/src/vehicle.ts b/src/vehicle.ts
index b4171cc6..78661738 100644
--- a/src/vehicle.ts
+++ b/src/vehicle.ts
@@ -76,16 +76,15 @@ export class Vehicle {
    */
   vin(): string {
     const bannedChars = ['o', 'i', 'q'];
-    return (
-      this.faker.random.alphaNumeric(10, { bannedChars: bannedChars }) +
-      this.faker.random.alpha({
-        count: 1,
-        upcase: true,
-        bannedChars: bannedChars,
-      }) +
-      this.faker.random.alphaNumeric(1, { bannedChars: bannedChars }) +
-      this.faker.datatype.number({ min: 10000, max: 100000 })
-    ) // return five digit #
+    return `${this.faker.random.alphaNumeric(10, {
+      bannedChars,
+    })}${this.faker.random.alpha({
+      count: 1,
+      upcase: true,
+      bannedChars,
+    })}${this.faker.random.alphaNumeric(1, {
+      bannedChars,
+    })}${this.faker.datatype.number({ min: 10000, max: 100000 })}` // return five digit #
       .toUpperCase();
   }
 
@@ -106,12 +105,16 @@ export class Vehicle {
    * faker.vehicle.vrm() // 'MF56UPA'
    */
   vrm(): string {
-    return (
-      this.faker.random.alpha({ count: 2, upcase: true }) +
-      this.faker.datatype.number({ min: 0, max: 9 }) +
-      this.faker.datatype.number({ min: 0, max: 9 }) +
-      this.faker.random.alpha({ count: 3, upcase: true })
-    ).toUpperCase();
+    return `${this.faker.random.alpha({
+      count: 2,
+      upcase: true,
+    })}${this.faker.datatype.number({
+      min: 0,
+      max: 9,
+    })}${this.faker.datatype.number({
+      min: 0,
+      max: 9,
+    })}${this.faker.random.alpha({ count: 3, upcase: true })}`.toUpperCase();
   }
 
   /**
diff --git a/src/vendor/mersenne.ts b/src/vendor/mersenne.ts
index 6a94522b..a908d8d8 100644
--- a/src/vendor/mersenne.ts
+++ b/src/vendor/mersenne.ts
@@ -193,7 +193,7 @@ function MersenneTwister19937(): void {
 
   /* generates a random number on [0,0xffffffff]-interval */
   //c//unsigned long genrand_int32(void)
-  this.genrand_int32 = function () {
+  this.genrand_int32 = function (): number {
     //c//unsigned long y;
     //c//static unsigned long mag01[2]={0x0UL, MATRIX_A};
     let y: number;
@@ -271,7 +271,8 @@ function MersenneTwister19937(): void {
   //c//double genrand_real3(void)
   this.genrand_real3 = function (): number {
     //c//return ((genrand_int32()) + 0.5)*(1.0/4294967296.0);
-    return (this.genrand_int32() + 0.5) * (1.0 / 4294967296.0);
+    // TODO @Shinigami92 2022-01-30: Rewrite this file to a class
+    return ((this.genrand_int32() as number) + 0.5) * (1.0 / 4294967296.0);
     /* divided by 2^32 */
   };
 
diff --git a/src/vendor/unique.ts b/src/vendor/unique.ts
index dbe82480..31056b03 100644
--- a/src/vendor/unique.ts
+++ b/src/vendor/unique.ts
@@ -87,7 +87,7 @@ export function exec<Method extends (args: Args) => string, Args extends any[]>(
   if (now - startTime >= opts.maxTime) {
     return errorMessage(
       now,
-      'Exceeded maxTime:' + opts.maxTime,
+      `Exceeded maxTime: ${opts.maxTime}`,
       // @ts-expect-error: we know that opts.startTime is defined
       opts
     );
@@ -96,7 +96,7 @@ export function exec<Method extends (args: Args) => string, Args extends any[]>(
   if (opts.currentIterations >= opts.maxRetries) {
     return errorMessage(
       now,
-      'Exceeded maxRetries:' + opts.maxRetries,
+      `Exceeded maxRetries: ${opts.maxRetries}`,
       // @ts-expect-error: we know that opts.startTime is defined
       opts
     );
diff --git a/src/vendor/user-agent.ts b/src/vendor/user-agent.ts
index 81cbeb3e..9218c6e5 100644
--- a/src/vendor/user-agent.ts
+++ b/src/vendor/user-agent.ts
@@ -73,7 +73,8 @@ export function generate(faker: Faker): string {
     }
 
     throw new TypeError(
-      'Invalid arguments passed to rnd. (' + (b ? a + ', ' + b : a) + ')'
+      // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+      `Invalid arguments passed to rnd. (${b ? `${a}, ${b}` : a})`
     );
   }
 
@@ -211,7 +212,7 @@ export function generate(faker: Faker): string {
     //generate a random revision
     //dots = 2 returns .x.y where x & y are between 0 and 9
     for (let x = 0; x < dots; x++) {
-      return_val += '.' + rnd(0, 9);
+      return_val += `.${rnd(0, 9)}`;
     }
     return return_val;
   }
@@ -221,13 +222,13 @@ export function generate(faker: Faker): string {
       return [rnd(1, 4), rnd(0, 9), rnd(10000, 99999), rnd(0, 9)].join('.');
     },
     nt() {
-      return rnd(5, 6) + '.' + rnd(0, 3);
+      return `${rnd(5, 6)}.${rnd(0, 3)}`;
     },
     ie() {
       return rnd(7, 11);
     },
     trident() {
-      return rnd(3, 7) + '.' + rnd(0, 1);
+      return `${rnd(3, 7)}.${rnd(0, 1)}`;
     },
     osx(delim?: string) {
       return [10, rnd(5, 10), rnd(0, 9)].join(delim || '.');
@@ -236,28 +237,28 @@ export function generate(faker: Faker): string {
       return [rnd(13, 39), 0, rnd(800, 899), 0].join('.');
     },
     presto() {
-      return '2.9.' + rnd(160, 190);
+      return `2.9.${rnd(160, 190)}`;
     },
     presto2() {
-      return rnd(10, 12) + '.00';
+      return `${rnd(10, 12)}.00`;
     },
     safari() {
-      return rnd(531, 538) + '.' + rnd(0, 2) + '.' + rnd(0, 2);
+      return `${rnd(531, 538)}.${rnd(0, 2)}.${rnd(0, 2)}`;
     },
   };
 
   const browser = {
     firefox(arch: Arch): string {
       //https://developer.mozilla.org/en-US/docs/Gecko_user_agent_string_reference
-      const firefox_ver = rnd(5, 15) + randomRevision(2),
+      const firefox_ver = `${rnd(5, 15)}${randomRevision(2)}`,
         gecko_ver = 'Gecko/20100101 Firefox/' + firefox_ver,
         proc = randomProc(arch),
         os_ver =
           arch === 'win'
-            ? '(Windows NT ' + version_string.nt() + (proc ? '; ' + proc : '')
+            ? '(Windows NT ' + version_string.nt() + (proc ? `; ${proc}` : '')
             : arch === 'mac'
-            ? '(Macintosh; ' + proc + ' Mac OS X ' + version_string.osx()
-            : '(X11; Linux ' + proc;
+            ? `(Macintosh; ${proc} Mac OS X ${version_string.osx()}`
+            : `(X11; Linux ${proc}`;
 
       return (
         'Mozilla/5.0 ' +
@@ -274,26 +275,16 @@ export function generate(faker: Faker): string {
 
       if (ver >= 11) {
         //http://msdn.microsoft.com/en-us/library/ie/hh869301(v=vs.85).aspx
-        return (
-          'Mozilla/5.0 (Windows NT 6.' +
-          rnd(1, 3) +
-          '; Trident/7.0; ' +
-          rnd(['Touch; ', '']) +
-          'rv:11.0) like Gecko'
-        );
+        return `Mozilla/5.0 (Windows NT 6.${rnd(1, 3)}; Trident/7.0; ${rnd([
+          'Touch; ',
+          '',
+        ])}rv:11.0) like Gecko`;
       }
 
       //http://msdn.microsoft.com/en-us/library/ie/ms537503(v=vs.85).aspx
-      return (
-        'Mozilla/5.0 (compatible; MSIE ' +
-        ver +
-        '.0; Windows NT ' +
-        version_string.nt() +
-        '; Trident/' +
-        version_string.trident() +
-        (rnd(0, 1) === 1 ? '; .NET CLR ' + version_string.net() : '') +
-        ')'
-      );
+      return `Mozilla/5.0 (compatible; MSIE ${ver}.0; Windows NT ${version_string.nt()}; Trident/${version_string.trident()}${
+        rnd(0, 1) === 1 ? '; .NET CLR ' + version_string.net() : ''
+      })`;
     },
 
     opera(arch: Arch): string {
@@ -306,44 +297,22 @@ export function generate(faker: Faker): string {
           ')',
         os_ver =
           arch === 'win'
-            ? '(Windows NT ' +
-              version_string.nt() +
-              '; U; ' +
-              randomLang() +
-              presto_ver
+            ? `(Windows NT ${version_string.nt()}; U; ${randomLang()}${presto_ver}`
             : arch === 'lin'
-            ? '(X11; Linux ' +
-              randomProc(arch) +
-              '; U; ' +
-              randomLang() +
-              presto_ver
-            : '(Macintosh; Intel Mac OS X ' +
-              version_string.osx() +
-              ' U; ' +
-              randomLang() +
-              ' Presto/' +
-              version_string.presto() +
-              ' Version/' +
-              version_string.presto2() +
-              ')';
+            ? `(X11; Linux ${randomProc(arch)}; U; ${randomLang()}${presto_ver}`
+            : `(Macintosh; Intel Mac OS X ${version_string.osx()} U; ${randomLang()} Presto/${version_string.presto()} Version/${version_string.presto2()})`;
 
-      return 'Opera/' + rnd(9, 14) + '.' + rnd(0, 99) + ' ' + os_ver;
+      return `Opera/${rnd(9, 14)}.${rnd(0, 99)} ${os_ver}`;
     },
 
     safari(arch: Arch): string {
       const safari = version_string.safari(),
-        ver = rnd(4, 7) + '.' + rnd(0, 1) + '.' + rnd(0, 10),
+        ver = `${rnd(4, 7)}.${rnd(0, 1)}.${rnd(0, 10)}`,
         os_ver =
           arch === 'mac'
-            ? '(Macintosh; ' +
-              randomProc('mac') +
-              ' Mac OS X ' +
-              version_string.osx('_') +
-              ' rv:' +
-              rnd(2, 6) +
-              '.0; ' +
-              randomLang() +
-              ') '
+            ? `(Macintosh; ${randomProc('mac')} Mac OS X ${version_string.osx(
+                '_'
+              )} rv:${rnd(2, 6)}.0; ${randomLang()}) `
             : '(Windows; U; Windows NT ' + version_string.nt() + ')';
 
       return (
@@ -362,14 +331,12 @@ export function generate(faker: Faker): string {
       const safari = version_string.safari(),
         os_ver =
           arch === 'mac'
-            ? '(Macintosh; ' +
-              randomProc('mac') +
-              ' Mac OS X ' +
-              version_string.osx('_') +
-              ') '
+            ? `(Macintosh; ${randomProc('mac')} Mac OS X ${version_string.osx(
+                '_'
+              )}) `
             : arch === 'win'
             ? '(Windows; U; Windows NT ' + version_string.nt() + ')'
-            : '(X11; Linux ' + randomProc(arch);
+            : `(X11; Linux ${randomProc(arch)}`;
 
       return (
         'Mozilla/5.0 ' +
diff --git a/test/database.spec.ts b/test/database.spec.ts
index 7117e97b..3b4177e4 100644
--- a/test/database.spec.ts
+++ b/test/database.spec.ts
@@ -13,10 +13,7 @@ describe('database', () => {
 
       expect(
         column,
-        'The column name should be equals ' +
-          expected +
-          '. Current is ' +
-          column
+        `The column name should be equals ${expected}. Current is ${column}`
       ).toBe(expected);
 
       spy_database_column.mockRestore();
@@ -34,10 +31,7 @@ describe('database', () => {
 
       expect(
         collation,
-        'The collation should be equals ' +
-          expected +
-          '. Current is ' +
-          collation
+        `The collation should be equals ${expected}. Current is ${collation}`
       ).toBe(expected);
 
       spy_database_collation.mockRestore();
@@ -55,7 +49,7 @@ describe('database', () => {
 
       expect(
         engine,
-        'The db engine should be equals ' + expected + '. Current is ' + engine
+        `The db engine should be equals ${expected}. Current is ${engine}`
       ).toBe(expected);
 
       spy_database_engine.mockRestore();
@@ -73,7 +67,7 @@ describe('database', () => {
 
       expect(
         type,
-        'The column type should be equals ' + expected + '. Current is ' + type
+        `The column type should be equals ${expected}. Current is ${type}`
       ).toBe(expected);
 
       spy_database_type.mockRestore();
diff --git a/test/finance.spec.ts b/test/finance.spec.ts
index 724c225e..f49e90e3 100644
--- a/test/finance.spec.ts
+++ b/test/finance.spec.ts
@@ -15,10 +15,7 @@ describe('finance', () => {
 
       expect(
         actual,
-        'The expected default account length is ' +
-          expected +
-          ' but it was ' +
-          actual
+        `The expected default account length is ${expected} but it was ${actual}`
       ).toBe(expected);
     });
 
@@ -31,10 +28,7 @@ describe('finance', () => {
 
       expect(
         actual,
-        'The expected default account length is ' +
-          expected +
-          ' but it was ' +
-          actual
+        `The expected default account length is ${expected} but it was ${actual}`
       ).toBe(expected);
     });
 
@@ -47,10 +41,7 @@ describe('finance', () => {
 
       expect(
         actual,
-        'The expected default account length is ' +
-          expected +
-          ' but it was ' +
-          actual
+        `The expected default account length is ${expected} but it was ${actual}`
       ).toBe(expected);
     });
   });
@@ -81,10 +72,7 @@ describe('finance', () => {
 
       expect(
         actual,
-        'The expected default mask length is ' +
-          expected +
-          ' but it was ' +
-          actual
+        `The expected default mask length is ${expected} but it was ${actual}`
       ).toBe(expected);
     });
 
@@ -102,10 +90,7 @@ describe('finance', () => {
 
       expect(
         actual,
-        'The expected default mask length is ' +
-          expected +
-          ' but it was ' +
-          actual
+        `The expected default mask length is ${expected} but it was ${actual}`
       ).toBe(expected);
     });
 
@@ -118,10 +103,7 @@ describe('finance', () => {
 
       expect(
         actual,
-        'The expected default mask length is ' +
-          expected +
-          ' but it was ' +
-          actual
+        `The expected default mask length is ${expected} but it was ${actual}`
       ).toBe(expected);
     });
 
@@ -135,10 +117,7 @@ describe('finance', () => {
 
       expect(
         actual,
-        'The expected match for parentheses is ' +
-          expected +
-          ' but it was ' +
-          actual
+        `The expected match for parentheses is ${expected} but it was ${actual}`
       ).toBe(expected);
     });
 
@@ -152,10 +131,7 @@ describe('finance', () => {
 
       expect(
         actual,
-        'The expected match for parentheses is ' +
-          expected +
-          ' but it was ' +
-          actual
+        `The expected match for parentheses is ${expected} but it was ${actual}`
       ).toBe(expected);
     });
 
@@ -387,9 +363,7 @@ describe('finance', () => {
     const ibanLib = require('../dist/cjs/iban');
 
     it('returns a random yet formally correct IBAN number', () => {
-      const iban =
-        // @ts-expect-error
-        faker.finance.iban();
+      const iban: string = faker.finance.iban();
       const bban = iban.substring(4) + iban.substring(0, 4);
 
       expect(
@@ -398,7 +372,7 @@ describe('finance', () => {
       ).toStrictEqual(1);
     });
     it('returns a specific and formally correct IBAN number', () => {
-      const iban = faker.finance.iban(false, 'DE');
+      const iban: string = faker.finance.iban(false, 'DE');
       const bban = iban.substring(4) + iban.substring(0, 4);
       const countryCode = iban.substring(0, 2);
 
@@ -421,9 +395,9 @@ describe('finance', () => {
     it('returns a random yet formally correct BIC number', () => {
       const bic = faker.finance.bic();
       const expr = new RegExp(
-        '^[A-Z]{4}(' +
-          ibanLib.iso3166.join('|') +
-          ')[A-Z2-9][A-NP-Z0-9]([A-Z0-9]{3})?$',
+        `^[A-Z]{4}(${ibanLib.iso3166.join(
+          '|'
+        )})[A-Z2-9][A-NP-Z0-9]([A-Z0-9]{3})?\$`,
         'i'
       );
 
diff --git a/test/finance_iban.spec.ts b/test/finance_iban.spec.ts
index 801ade34..d11a9568 100644
--- a/test/finance_iban.spec.ts
+++ b/test/finance_iban.spec.ts
@@ -5,7 +5,7 @@ import ibanLib from '../dist/cjs/iban';
 
 console.log(ibanLib);
 
-function getAnIbanByCountry(countryCode) {
+function getAnIbanByCountry(countryCode: string): string {
   let iban =
     // @ts-expect-error
     faker.finance.iban();
@@ -23,9 +23,9 @@ function getAnIbanByCountry(countryCode) {
     console.log('Not found with 10000 seed, vraiment pas de bol');
   } else if (countTry < maxTry) {
     console.log(
-      'you can optimize this helper by add faker.seed(' +
-        (100000 - 1 - countTry) +
-        ') before the call of getAnIbanByCountry()'
+      `you can optimize this helper by add faker.seed(${
+        100000 - 1 - countTry
+      }) before the call of getAnIbanByCountry()`
     );
   }
   // console.log(iban);
@@ -53,7 +53,7 @@ describe('finance_iban.js', () => {
 
       expect(
         22,
-        'GE IBAN would be 22 chars length, given is ' + iban.length
+        `GE IBAN would be 22 chars length, given is ${iban.length}`
       ).toBe(iban.length);
 
       expect(
@@ -112,7 +112,7 @@ describe('finance_iban.js', () => {
 
       expect(
         24,
-        'PK IBAN would be 24 chars length, given is ' + iban.length
+        `PK IBAN would be 24 chars length, given is ${iban.length}`
       ).toBe(iban.length);
 
       expect(
@@ -178,7 +178,7 @@ describe('finance_iban.js', () => {
 
       expect(
         26,
-        'PK IBAN would be 26 chars length, given is ' + iban.length
+        `PK IBAN would be 26 chars length, given is ${iban.length}`
       ).toBe(iban.length);
 
       expect(
@@ -251,7 +251,7 @@ describe('finance_iban.js', () => {
 
       expect(
         28,
-        'AZ IBAN would be 28 chars length, given is ' + iban.length
+        `AZ IBAN would be 28 chars length, given is ${iban.length}`
       ).toBe(iban.length);
 
       expect(