chore: prefer string templates over string concatenation (#732)

18 files changed, 82 insertions, 130 deletions

diff --git a/src/address.ts b/src/address.ts
index 83fa675b..e0fb6bf2 100644
--- a/src/address.ts
+++ b/src/address.ts
@@ -230,7 +230,7 @@ export class Address {
     let result: string;
     let suffix = this.streetSuffix();
     if (suffix !== '') {
-      suffix = ' ' + suffix;
+      suffix = ` ${suffix}`;
     }
 
     switch (this.faker.datatype.number(1)) {
@@ -381,7 +381,7 @@ export class Address {
       .number({
         min,
         max,
-        precision: parseFloat((0.0).toPrecision(precision) + '1'),
+        precision: parseFloat(`${(0.0).toPrecision(precision)}1`),
       })
       .toFixed(precision);
   }
@@ -406,7 +406,7 @@ export class Address {
       .number({
         max: max,
         min: min,
-        precision: parseFloat((0.0).toPrecision(precision) + '1'),
+        precision: parseFloat(`${(0.0).toPrecision(precision)}1`),
       })
       .toFixed(precision);
   }
diff --git a/src/commerce.ts b/src/commerce.ts
index a94d7b85..9d0a5731 100644
--- a/src/commerce.ts
+++ b/src/commerce.ts
@@ -45,13 +45,7 @@ export class Commerce {
    * faker.commerce.productName() // 'Incredible Soft Gloves'
    */
   productName(): string {
-    return (
-      this.productAdjective() +
-      ' ' +
-      this.productMaterial() +
-      ' ' +
-      this.product()
-    );
+    return `${this.productAdjective()} ${this.productMaterial()} ${this.product()}`;
   }
 
   /**
diff --git a/src/datatype.ts b/src/datatype.ts
index 29a4950b..90211b69 100644
--- a/src/datatype.ts
+++ b/src/datatype.ts
@@ -243,7 +243,7 @@ export class Datatype {
       ]);
     }
 
-    return '0x' + wholeString;
+    return `0x${wholeString}`;
   }
 
   /**
diff --git a/src/fake.ts b/src/fake.ts
index d478d01e..4a22e2ff 100644
--- a/src/fake.ts
+++ b/src/fake.ts
@@ -89,11 +89,11 @@ export class Fake {
     const parts = method.split('.');
 
     if (this.faker[parts[0]] == null) {
-      throw new FakerError('Invalid module: ' + parts[0]);
+      throw new FakerError(`Invalid module: ${parts[0]}`);
     }
 
     if (this.faker[parts[0]][parts[1]] == null) {
-      throw new FakerError('Invalid method: ' + parts[0] + '.' + parts[1]);
+      throw new FakerError(`Invalid method: ${parts[0]}.${parts[1]}`);
     }
 
     // assign the function from the module.function namespace
diff --git a/src/finance.ts b/src/finance.ts
index ea4174d6..2214088d 100644
--- a/src/finance.ts
+++ b/src/finance.ts
@@ -96,7 +96,7 @@ export class Finance {
     let template = '';
 
     for (let i = 0; i < length; i++) {
-      template = template + '#';
+      template = `${template}#`;
     }
 
     //prefix with ellipsis
@@ -332,7 +332,7 @@ export class Finance {
       : this.faker.random.arrayElement(iban.formats);
 
     if (!ibanFormat) {
-      throw new FakerError('Country code ' + countryCode + ' not supported.');
+      throw new FakerError(`Country code ${countryCode} not supported.`);
     }
 
     let s = '';
@@ -387,20 +387,21 @@ export class Finance {
   bic(): string {
     const vowels = ['A', 'E', 'I', 'O', 'U'];
     const prob = this.faker.datatype.number(100);
-    return (
-      this.faker.helpers.replaceSymbols('???') +
-      this.faker.random.arrayElement(vowels) +
-      this.faker.random.arrayElement(iban.iso3166) +
-      this.faker.helpers.replaceSymbols('?') +
-      '1' +
-      (prob < 10
+
+    return [
+      this.faker.helpers.replaceSymbols('???'),
+      this.faker.random.arrayElement(vowels),
+      this.faker.random.arrayElement(iban.iso3166),
+      this.faker.helpers.replaceSymbols('?'),
+      '1',
+      prob < 10
         ? this.faker.helpers.replaceSymbols(
-            '?' + this.faker.random.arrayElement(vowels) + '?'
+            `?${this.faker.random.arrayElement(vowels)}?`
           )
         : prob < 40
         ? this.faker.helpers.replaceSymbols('###')
-        : '')
-    );
+        : '',
+    ].join('');
   }
 
   /**
@@ -418,18 +419,7 @@ export class Finance {
     const company = transaction.business;
     const card = this.mask();
     const currency = this.currencyCode();
-    return (
-      transactionType +
-      ' transaction at ' +
-      company +
-      ' using card ending with ***' +
-      card +
-      ' for ' +
-      currency +
-      ' ' +
-      amount +
-      ' in account ***' +
-      account
-    );
+
+    return `${transactionType} transaction at ${company} using card ending with ***${card} for ${currency} ${amount} in account ***${account}`;
   }
 }
diff --git a/src/git.ts b/src/git.ts
index 6c82e48d..94144043 100644
--- a/src/git.ts
+++ b/src/git.ts
@@ -42,7 +42,7 @@ export class Git {
   branch(): string {
     const noun = this.faker.hacker.noun().replace(' ', '-');
     const verb = this.faker.hacker.verb().replace(' ', '-');
-    return noun + '-' + verb;
+    return `${noun}-${verb}`;
   }
 
   /**
diff --git a/src/helpers.ts b/src/helpers.ts
index 5b26bd9d..be3ce8f5 100644
--- a/src/helpers.ts
+++ b/src/helpers.ts
@@ -481,7 +481,7 @@ export class Helpers {
       return '';
     }
     for (const p in data) {
-      const re = new RegExp('{{' + p + '}}', 'g');
+      const re = new RegExp(`{{${p}}}`, 'g');
       const value = data[p];
       if (typeof value === 'string') {
         str = str.replace(re, value);
diff --git a/src/image.ts b/src/image.ts
index 2f4444ab..8aeab602 100644
--- a/src/image.ts
+++ b/src/image.ts
@@ -104,7 +104,7 @@ export class Image {
     }
     let url = `${protocol}loremflickr.com/${width}/${height}`;
     if (category != null) {
-      url += '/' + category;
+      url += `/${category}`;
     }
 
     if (randomize) {
diff --git a/src/image_providers/lorempicsum.ts b/src/image_providers/lorempicsum.ts
index 9fed741e..f28b1e8f 100644
--- a/src/image_providers/lorempicsum.ts
+++ b/src/image_providers/lorempicsum.ts
@@ -104,7 +104,7 @@ export class LoremPicsum {
     let url = 'https://picsum.photos';
 
     if (seed) {
-      url += '/seed/' + seed;
+      url += `/seed/${seed}`;
     }
 
     url += `/${width}/${height}`;
@@ -114,7 +114,7 @@ export class LoremPicsum {
     }
 
     if (grayscale) {
-      return url + '?grayscale';
+      return `${url}?grayscale`;
     }
 
     if (blur) {
diff --git a/src/image_providers/lorempixel.ts b/src/image_providers/lorempixel.ts
index 310ba45a..914f1066 100644
--- a/src/image_providers/lorempixel.ts
+++ b/src/image_providers/lorempixel.ts
@@ -67,7 +67,7 @@ export class Lorempixel {
 
     let url = `https://lorempixel.com/${width}/${height}`;
     if (category != null) {
-      url += '/' + category;
+      url += `/${category}`;
     }
 
     if (randomize) {
diff --git a/src/image_providers/unsplash.ts b/src/image_providers/unsplash.ts
index dd8abd37..994b2a04 100644
--- a/src/image_providers/unsplash.ts
+++ b/src/image_providers/unsplash.ts
@@ -59,7 +59,7 @@ export class Unsplash {
     let url = 'https://source.unsplash.com';
 
     if (category != null) {
-      url += '/category/' + category;
+      url += `/category/${category}`;
     }
 
     url += `/${width}x${height}`;
@@ -67,7 +67,7 @@ export class Unsplash {
     if (keyword != null) {
       const keywordFormat = /^([A-Za-z0-9].+,[A-Za-z0-9]+)$|^([A-Za-z0-9]+)$/;
       if (keywordFormat.test(keyword)) {
-        url += '?' + keyword;
+        url += `?${keyword}`;
       }
     }
 
diff --git a/src/internal/deprecated.ts b/src/internal/deprecated.ts
index 7f20c24f..ab67b60a 100644
--- a/src/internal/deprecated.ts
+++ b/src/internal/deprecated.ts
@@ -25,5 +25,5 @@ export function deprecated(opts: DeprecatedOptions): void {
     message += `. Please use ${opts.proposed} instead`;
   }
 
-  console.warn(message + '.');
+  console.warn(`${message}.`);
 }
diff --git a/src/internet.ts b/src/internet.ts
index 7e9b72a4..fa4ae6e8 100644
--- a/src/internet.ts
+++ b/src/internet.ts
@@ -67,9 +67,11 @@ export class Internet {
       this.faker.random.arrayElement(
         this.faker.definitions.internet.free_email
       );
+
     let localPart: string = this.faker.helpers.slugify(
       this.userName(firstName, lastName)
     );
+
     if (options?.allowSpecialCharacters) {
       const usernameChars: string[] = '._-'.split('');
       const specialChars: string[] = ".!#$%&'*+-/=?^_`{|}~".split('');
@@ -78,6 +80,7 @@ export class Internet {
         this.faker.random.arrayElement(specialChars)
       );
     }
+
     return `${localPart}@${provider}`;
   }
 
@@ -184,7 +187,7 @@ export class Internet {
    * faker.internet.url() // 'https://remarkable-hackwork.info'
    */
   url(): string {
-    return this.protocol() + '://' + this.domainName();
+    return `${this.protocol()}://${this.domainName()}`;
   }
 
   /**
@@ -194,7 +197,7 @@ export class Internet {
    * faker.internet.domainName() // 'slow-timer.info'
    */
   domainName(): string {
-    return this.domainWord() + '.' + this.domainSuffix();
+    return `${this.domainWord()}.${this.domainSuffix()}`;
   }
 
   /**
@@ -218,7 +221,7 @@ export class Internet {
    * faker.internet.domainWord() // 'weird-cytoplasm'
    */
   domainWord(): string {
-    return (this.faker.word.adjective() + '-' + this.faker.word.noun())
+    return `${this.faker.word.adjective()}-${this.faker.word.noun()}`
       .replace(/([\\~#&*{}/:<>?|\"'])/gi, '')
       .replace(/\s/g, '-')
       .replace(/-{2,}/g, '-')
@@ -316,41 +319,34 @@ export class Internet {
   }
 
   /**
-   * Generates a random css hex color code.
+   * Generates a random css hex color code in aesthetically pleasing color palette.
    *
-   * @param baseRed255 The optional base red. Used for aesthetically pleasing color palettes. Supports values between `0` and `255`. Defaults to `0`.
-   * @param baseGreen255 The optional base green. Used for aesthetically pleasing color palettes. Supports values between `0` and `255`. Defaults to `0`.
-   * @param baseBlue255 The optional base blue. Used for aesthetically pleasing color palettes. Supports values between `0` and `255`. Defaults to `0`.
+   * Based on
+   * http://stackoverflow.com/questions/43044/algorithm-to-randomly-generate-an-aesthetically-pleasing-color-palette
+   *
+   * @param redBase The optional base red in range between `0` and `255`. Defaults to `0`.
+   * @param greenBase The optional base green in range between `0` and `255`. Defaults to `0`.
+   * @param blueBase The optional base blue in range between `0` and `255`. Defaults to `0`.
    *
    * @example
    * faker.internet.color() // '#30686e'
    * faker.internet.color(100, 100, 100) // '#4e5f8b'
    */
   color(
-    baseRed255: number = 0,
-    baseGreen255: number = 0,
-    baseBlue255: number = 0
+    redBase: number = 0,
+    greenBase: number = 0,
+    blueBase: number = 0
   ): string {
-    // based on awesome response : http://stackoverflow.com/questions/43044/algorithm-to-randomly-generate-an-aesthetically-pleasing-color-palette
-    const red = Math.floor((this.faker.datatype.number(256) + baseRed255) / 2);
-    const green = Math.floor(
-      (this.faker.datatype.number(256) + baseGreen255) / 2
-    );
-    const blue = Math.floor(
-      (this.faker.datatype.number(256) + baseBlue255) / 2
-    );
-    const redStr = red.toString(16);
-    const greenStr = green.toString(16);
-    const blueStr = blue.toString(16);
-    return (
-      '#' +
-      (redStr.length === 1 ? '0' : '') +
-      redStr +
-      (greenStr.length === 1 ? '0' : '') +
-      greenStr +
-      (blueStr.length === 1 ? '0' : '') +
-      blueStr
-    );
+    const colorFromBase = (base: number): string =>
+      Math.floor((this.faker.datatype.number(256) + base) / 2)
+        .toString(16)
+        .padStart(2, '0');
+
+    const red = colorFromBase(redBase);
+    const green = colorFromBase(greenBase);
+    const blue = colorFromBase(blueBase);
+
+    return `#${red}${green}${blue}`;
   }
 
   /**
diff --git a/src/lorem.ts b/src/lorem.ts
index 103dd6a7..14cc2f6b 100644
--- a/src/lorem.ts
+++ b/src/lorem.ts
@@ -67,7 +67,7 @@ export class Lorem {
     }
 
     const sentence = this.words(wordCount);
-    return sentence.charAt(0).toUpperCase() + sentence.slice(1) + '.';
+    return `${sentence.charAt(0).toUpperCase() + sentence.slice(1)}.`;
   }
 
   /**
diff --git a/src/mersenne.ts b/src/mersenne.ts
index 21f52f6c..c8f531f2 100644
--- a/src/mersenne.ts
+++ b/src/mersenne.ts
@@ -48,7 +48,7 @@ export class Mersenne {
   seed(S: number): void {
     if (typeof S !== 'number') {
       throw new FakerError(
-        'seed(S) must take numeric argument; is ' + typeof S
+        `seed(S) must take numeric argument; is ${typeof S}`
       );
     }
 
@@ -64,7 +64,7 @@ export class Mersenne {
   seed_array(A: number[]): void {
     if (typeof A !== 'object') {
       throw new FakerError(
-        'seed_array(A) must take array of numbers; is ' + typeof A
+        `seed_array(A) must take array of numbers; is ${typeof A}`
       );
     }
 
diff --git a/src/name.ts b/src/name.ts
index b96eb8db..41a6075a 100644
--- a/src/name.ts
+++ b/src/name.ts
@@ -213,18 +213,18 @@ export class Name {
       case 0:
         prefix = this.prefix(gender);
         if (prefix) {
-          return prefix + ' ' + firstName + ' ' + lastName;
+          return `${prefix} ${firstName} ${lastName}`;
         }
       // TODO @Shinigami92 2022-01-21: Not sure if this fallthrough is wanted
       // eslint-disable-next-line no-fallthrough
       case 1:
         suffix = this.suffix();
         if (suffix) {
-          return firstName + ' ' + lastName + ' ' + suffix;
+          return `${firstName} ${lastName} ${suffix}`;
         }
     }
 
-    return firstName + ' ' + lastName;
+    return `${firstName} ${lastName}`;
   }
 
   /**
@@ -309,7 +309,7 @@ export class Name {
    * faker.name.jobTitle() // 'Global Accounts Engineer'
    */
   jobTitle(): string {
-    return this.jobDescriptor() + ' ' + this.jobArea() + ' ' + this.jobType();
+    return `${this.jobDescriptor()} ${this.jobArea()} ${this.jobType()}`;
   }
 
   /**
diff --git a/src/system.ts b/src/system.ts
index 16ddd876..05d0bf44 100644
--- a/src/system.ts
+++ b/src/system.ts
@@ -54,9 +54,9 @@ export class System {
    * faker.system.fileName() // 'self_enabling_accountability_toys.kpt'
    */
   fileName(): string {
-    let str = this.faker.random.words();
-    str = str.toLowerCase().replace(/\W/g, '_') + '.' + this.fileExt();
-    return str;
+    const str = this.faker.random.words().toLowerCase().replace(/\W/g, '_');
+
+    return `${str}.${this.fileExt()}`;
   }
 
   /**
@@ -68,10 +68,9 @@ export class System {
    * faker.system.commonFileName('txt') // 'global_borders_wyoming.txt'
    */
   commonFileName(ext?: string): string {
-    let str = this.faker.random.words();
-    str = str.toLowerCase().replace(/\W/g, '_');
-    str += '.' + (ext || this.commonFileExt());
-    return str;
+    const str = this.faker.random.words().toLowerCase().replace(/\W/g, '_');
+
+    return `${str}.${ext || this.commonFileExt()}`;
   }
 
   /**
diff --git a/src/utils/user-agent.ts b/src/utils/user-agent.ts
index 7f7e8cbb..5ff18c2a 100644
--- a/src/utils/user-agent.ts
+++ b/src/utils/user-agent.ts
@@ -267,23 +267,19 @@ export function generate(faker: Faker): string {
     firefox(arch: Arch): string {
       //https://developer.mozilla.org/en-US/docs/Gecko_user_agent_string_reference
       const firefox_ver = `${rnd(5, 15)}${randomRevision(2)}`,
-        gecko_ver = 'Gecko/20100101 Firefox/' + firefox_ver,
+        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}`;
 
-      return (
-        'Mozilla/5.0 ' +
-        os_ver +
-        '; rv:' +
-        firefox_ver.slice(0, -2) +
-        ') ' +
-        gecko_ver
-      );
+      return `Mozilla/5.0 ${os_ver}; rv:${firefox_ver.slice(
+        0,
+        -2
+      )}) ${gecko_ver}`;
     },
 
     iexplorer(): string {
@@ -299,18 +295,13 @@ export function generate(faker: Faker): string {
 
       //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() : ''
+        rnd(0, 1) === 1 ? `; .NET CLR ${version_string.net()}` : ''
       })`;
     },
 
     opera(arch: Arch): string {
       //http://www.opera.com/docs/history/
-      const presto_ver =
-          ' Presto/' +
-          version_string.presto() +
-          ' Version/' +
-          version_string.presto2() +
-          ')',
+      const presto_ver = ` Presto/${version_string.presto()} Version/${version_string.presto2()})`,
         os_ver =
           arch === 'win'
             ? `(Windows NT ${version_string.nt()}; U; ${randomLang()}${presto_ver}`
@@ -329,18 +320,9 @@ export function generate(faker: Faker): string {
             ? `(Macintosh; ${randomProc('mac')} Mac OS X ${version_string.osx(
                 '_'
               )} rv:${rnd(2, 6)}.0; ${randomLang()}) `
-            : '(Windows; U; Windows NT ' + version_string.nt() + ')';
+            : `(Windows; U; Windows NT ${version_string.nt()})`;
 
-      return (
-        'Mozilla/5.0 ' +
-        os_ver +
-        'AppleWebKit/' +
-        safari +
-        ' (KHTML, like Gecko) Version/' +
-        ver +
-        ' Safari/' +
-        safari
-      );
+      return `Mozilla/5.0 ${os_ver}AppleWebKit/${safari} (KHTML, like Gecko) Version/${ver} Safari/${safari}`;
     },
 
     chrome(arch: Arch): string {
@@ -351,19 +333,10 @@ export function generate(faker: Faker): string {
                 '_'
               )}) `
             : arch === 'win'
-            ? '(Windows; U; Windows NT ' + version_string.nt() + ')'
+            ? `(Windows; U; Windows NT ${version_string.nt()})`
             : `(X11; Linux ${randomProc(arch)}`;
 
-      return (
-        'Mozilla/5.0 ' +
-        os_ver +
-        ' AppleWebKit/' +
-        safari +
-        ' (KHTML, like Gecko) Chrome/' +
-        version_string.chrome() +
-        ' Safari/' +
-        safari
-      );
+      return `Mozilla/5.0 ${os_ver} AppleWebKit/${safari} (KHTML, like Gecko) Chrome/${version_string.chrome()} Safari/${safari}`;
     },
   };