feat: helpers that allows working with mime type and file extensions

spec/array.spec.ts

@@ -240,18 +240,8 @@ describe('intersection', () => {
     })
 
     it('supports empty array', () => {
-        expect(
-            intersection([
-                [],
-                [2, 3],
-            ])
-        ).toEqual([])
-        expect(
-            intersection([
-                [2, 3],
-                [],
-            ])
-        ).toEqual([])
+        expect(intersection([[], [2, 3]])).toEqual([])
+        expect(intersection([[2, 3], []])).toEqual([])
     })
 
     it('supports key callback', () => {

spec/encoding.spec.ts

@@ -16,9 +16,9 @@ describe('base64Decode', () => {
 
 describe('base64Decode', () => {
     it('decodes string', () => {
-        expect(base64Decode('cnTEl8SZcmZndDU4xK/ElznEr8SXxaErxJcqLeOBr+S4qg==')).toBe(
-            'rtėęrfgt58įė9įėš+ė*-は个'
-        )
+        expect(
+            base64Decode('cnTEl8SZcmZndDU4xK/ElznEr8SXxaErxJcqLeOBr+S4qg==')
+        ).toBe('rtėęrfgt58įė9įėš+ė*-は个')
     })
 })
 

spec/files.spec.ts

@@ -1,4 +1,4 @@
-import { formatBytes, getFileParts, parseSize } from '../src'
+import { formatBytes, getFileParts, parseSize, getMimeType, getExtension } from '../src'
 
 describe('formatBytes', () => {
     it('handles zero', () => {
@@ -64,3 +64,55 @@ describe('getFileParts', () => {
         expect(getFileParts('/my.home/.data')).toEqual(['/my.home/.data', ''])
     })
 })
+
+describe('getMimeType', () => {
+    it('returns undefined for unknown extension', () => {
+        expect(getMimeType('myfile.unknown')).toBeUndefined()
+    })
+
+    it('returns undefined for empty extension', () => {
+        expect(getMimeType('myfile')).toBeUndefined()
+    })
+
+    it('returns undefined for empty file name', () => {
+        expect(getMimeType('')).toBeUndefined()
+    })
+
+    it('returns undefined for empty file name and empty extension', () => {
+        expect(getMimeType('.')).toBeUndefined()
+    })
+
+    it('returns undefined for dot file', () => {
+        expect(getMimeType('.data')).toBeUndefined()
+    })
+
+    it('returns mime type for text file with extension', () => {
+        expect(getMimeType('data.txt')).toEqual('text/plain')
+    })
+
+    it('returns mime type for json', () => {
+        expect(getMimeType('json')).toEqual('application/json')
+    })
+})
+
+describe('getExtension', () => {
+    it('returns undefined for unknown mime type', () => {
+        expect(getExtension('application/unknown')).toBeUndefined()
+    })
+
+    it('returns undefined for empty mime type', () => {
+        expect(getExtension('')).toBeUndefined()
+    })
+
+    it('returns undefined for empty mime type and empty extension', () => {
+        expect(getExtension('.')).toBeUndefined()
+    })
+
+    it('returns extension for text file with mime type', () => {
+        expect(getExtension('text/plain')).toEqual('txt')
+    })
+
+    it('returns extension for json', () => {
+        expect(getExtension('application/json')).toEqual('json')
+    })
+})

spec/guards.spec.ts

@@ -20,15 +20,15 @@ describe('isPlainObject', () => {
     it('checks if is plain object', () => {
         expect(isPlainObject({ a: 1 })).toBeTruthy()
         expect(isPlainObject({})).toBeTruthy()
-        expect(isPlainObject({ a: [1, {}]})).toBeTruthy()
+        expect(isPlainObject({ a: [1, {}] })).toBeTruthy()
         expect(isPlainObject('a')).toBeFalsy()
         expect(isPlainObject(1)).toBeFalsy()
         expect(isPlainObject(new Boolean(false))).toBeFalsy()
         expect(isPlainObject(new Date())).toBeFalsy()
         expect(isPlainObject([])).toBeFalsy()
         expect(isPlainObject(null)).toBeFalsy()
         expect(isPlainObject(undefined)).toBeFalsy()
-        expect(isPlainObject(new class A {})).toBeFalsy()
+        expect(isPlainObject(new (class A {})())).toBeFalsy()
     })
 })
 

spec/object.spec.ts

@@ -110,15 +110,21 @@ describe('merge', () => {
     })
 
     it('merges arrays', () => {
-        expect(merge([1, 2], [3, 4], { arrayPolicy: 'merge' })).toEqual([1, 2, 3, 4])
+        expect(merge([1, 2], [3, 4], { arrayPolicy: 'merge' })).toEqual([
+            1, 2, 3, 4,
+        ])
     })
 
     it('supports custom array merge function', () => {
-        expect(merge([1, 2], [3, 4], { arrayPolicy: (a, b) => b.concat(a) })).toEqual([3, 4, 1, 2])
+        expect(
+            merge([1, 2], [3, 4], { arrayPolicy: (a, b) => b.concat(a) })
+        ).toEqual([3, 4, 1, 2])
     })
 
     it('skip nulls', () => {
-        expect(merge({ a: 1 }, { a: null }, { skipNulls: true })).toEqual({ a: 1 })
+        expect(merge({ a: 1 }, { a: null }, { skipNulls: true })).toEqual({
+            a: 1,
+        })
     })
 })
 
@@ -273,20 +279,16 @@ describe('convertToNested', () => {
 
 describe('getByKey', () => {
     it('get value by string key', () => {
-        expect(
-            getByKey({ a: { b: [1, {a: 10}]}}, 'a.b.1.a')
-        ).toBe(10)
+        expect(getByKey({ a: { b: [1, { a: 10 }] } }, 'a.b.1.a')).toBe(10)
     })
 
     it('get string value by key path list', () => {
-        expect(
-            getByKey({ a: { b: [1, {a: 10}]}}, ['a', 'b', 1, 'a'])
-        ).toBe(10)
+        expect(getByKey({ a: { b: [1, { a: 10 }] } }, ['a', 'b', 1, 'a'])).toBe(
+            10
+        )
     })
 
     it('get unknown property', () => {
-        expect(
-            getByKey(new Date(), ['a', 'b', 1, 'a'])
-        ).toBeUndefined()
+        expect(getByKey(new Date(), ['a', 'b', 1, 'a'])).toBeUndefined()
     })
 })

spec/string.spec.ts

@@ -1,4 +1,11 @@
-import { truncate, extractWords, camelCase, pascalCase, titleCase, isLetter } from '../src'
+import {
+    truncate,
+    extractWords,
+    camelCase,
+    pascalCase,
+    titleCase,
+    isLetter,
+} from '../src'
 
 describe('truncate', () => {
     it('truncates string', () => {
@@ -58,6 +65,8 @@ describe('isLetter', () => {
 
 describe('titleCase', () => {
     it('changes string', () => {
-        expect(titleCase('hello-world FTW,abc999t t')).toEqual('Hello-World Ftw,Abc999T T')
+        expect(titleCase('hello-world FTW,abc999t t')).toEqual(
+            'Hello-World Ftw,Abc999T T'
+        )
     })
 })