From 400427a2c16e5b92cb7add1262809a123cf7d5af Mon Sep 17 00:00:00 2001 From: 30secondsofcode <30secondsofcode@gmail.com> Date: Wed, 3 Oct 2018 19:19:18 +0000 Subject: [PATCH] Travis build: 586 --- README.md | 113 +++++++++++++++++++++++++++++++++++++++++++++ docs/adapter.html | 2 +- docs/browser.html | 2 +- docs/date.html | 2 +- docs/function.html | 2 +- docs/index.html | 2 +- docs/math.html | 2 +- docs/node.html | 32 ++++++++++++- docs/object.html | 2 +- docs/string.html | 2 +- docs/type.html | 2 +- docs/utility.html | 2 +- 12 files changed, 154 insertions(+), 11 deletions(-) diff --git a/README.md b/README.md index 3c5ca8629..c4da8e814 100644 --- a/README.md +++ b/README.md @@ -353,7 +353,11 @@ average(1, 2, 3); * [`colorize`](#colorize) * [`hasFlags`](#hasflags) * [`hashNode`](#hashnode) +* [`isDuplexStream`](#isduplexstream) +* [`isReadableStream`](#isreadablestream) +* [`isStream`](#isstream) * [`isTravisCI`](#istravisci) +* [`isWritableStream`](#iswritablestream) * [`JSONToFile`](#jsontofile) * [`readFileLines`](#readfilelines) * [`untildify`](#untildify) @@ -6290,6 +6294,87 @@ hashNode(JSON.stringify({ a: 'a', b: [1, 2, 3, 4], foo: { c: 'bar' } })).then(co
[⬆ Back to top](#table-of-contents) +### isDuplexStream + +Checks if the given argument is a duplex (readable and writable) stream. + +Check if the value is different from `null`, use `typeof` to check if a value is of type `object` and the `pipe` property is of type `function`. +Additionally check if the `typeof` the `_read`, `_write` and `_readableState`, `_writableState` properties are `function` and `object` respectively. + +```js +const isDuplexStream = val => + val !== null && + typeof val === 'object' && + typeof val.pipe === 'function' && + typeof val.pipe === 'function' && + typeof val._read === 'function' && + typeof val._readableState === 'object' && + typeof val._write === 'function' && + typeof val._writableState === 'object'; +``` + +
+Examples + +```js +const Stream = require('stream'); +isDuplexStream(new Stream.Duplex()); // true +``` + +
+ +
[⬆ Back to top](#table-of-contents) + +### isReadableStream + +Checks if the given argument is a readable stream. + +Check if the value is different from `null`, use `typeof` to check if the value is of type `object` and the `pipe` property is of type `function`. +Additionally check if the `typeof` the `_read` and `_readableState` properties are `function` and `object` respectively. + +```js +const isReadableStream = val => + val !== null && + typeof val === 'object' && + typeof val.pipe === 'function' && + typeof val._read === 'function' && + typeof val._readableState === 'object'; +``` + +
+Examples + +```js +const fs = require('fs'); +isReadableStream(fs.createReadStream('test.txt')); // true +``` + +
+ +
[⬆ Back to top](#table-of-contents) + +### isStream + +Checks if the given argument is a stream. + +Check if the value is different from `null`, use `typeof` to check if the value is of type `object` and the `pipe` property is of type `function`. + +```js +const isStream = val => val !== null && typeof val === 'object' && typeof val.pipe === 'function'; +``` + +
+Examples + +```js +const fs = require('fs'); +isStream(fs.createReadStream('test.txt')); // true +``` + +
+ +
[⬆ Back to top](#table-of-contents) + ### isTravisCI Checks if the current environment is [Travis CI](https://travis-ci.org/). @@ -6311,6 +6396,34 @@ isTravisCI(); // true (if code is running on Travis CI)
[⬆ Back to top](#table-of-contents) +### isWritableStream + +Checks if the given argument is a writable stream. + +Check if the value is different from `null`, use `typeof` to check if the value is of type `object` and the `pipe` property is of type `function`. +Additionally check if the `typeof` the `_write` and `_writableState` properties are `function` and `object` respectively. + +```js +const isWritableStream = val => + val !== null && + typeof val === 'object' && + typeof val.pipe === 'function' && + typeof val._write === 'function' && + typeof val._writableState === 'object'; +``` + +
+Examples + +```js +const fs = require('fs'); +isWritableStream(fs.createWriteStream('test.txt')); // true +``` + +
+ +
[⬆ Back to top](#table-of-contents) + ### JSONToFile Writes a JSON object to a file. diff --git a/docs/adapter.html b/docs/adapter.html index 313522f6d..2df1ea18d 100644 --- a/docs/adapter.html +++ b/docs/adapter.html @@ -91,7 +91,7 @@ },1700); } }, false); - }

logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.



Adapter

ary

Creates a function that accepts up to n arguments, ignoring any additional arguments.

Call the provided function, fn, with up to n arguments, using Array.prototype.slice(0,n) and the spread operator (...).

const ary = (fn, n) => (...args) => fn(...args.slice(0, n));
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Adapter
ary
Creates a function that accepts up to n arguments, ignoring any additional arguments.
Call the provided function, fn, with up to n arguments, using Array.prototype.slice(0,n) and the spread operator (...).
const ary = (fn, n) => (...args) => fn(...args.slice(0, n));
 
const firstTwoMax = ary(Math.max, 2);
 [[2, 6, 'a'], [8, 4, 6], [10]].map(x => firstTwoMax(...x)); // [6, 8, 10]
 
call
Given a key and a set of arguments, call them when given a context. Primarily useful in composition.
Use a closure to call a stored key with stored arguments.
const call = (key, ...args) => context => context[key](...args);
diff --git a/docs/browser.html b/docs/browser.html
index 36bfe3f1e..fe9ba6c90 100644
--- a/docs/browser.html
+++ b/docs/browser.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Browser
arrayToHtmlList
Converts the given array elements into <li> tags and appends them to the list of the given id.
Use Array.prototype.map(), document.querySelector(), and an anonymous inner closure to create a list of html tags.
const arrayToHtmlList = (arr, listID) =>
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Browser
arrayToHtmlList
Converts the given array elements into <li> tags and appends them to the list of the given id.
Use Array.prototype.map(), document.querySelector(), and an anonymous inner closure to create a list of html tags.
const arrayToHtmlList = (arr, listID) =>
   (el => (
     (el = document.querySelector('#' + listID)),
     (el.innerHTML += arr.map(item => `<li>${item}</li>`).join(''))
diff --git a/docs/date.html b/docs/date.html
index 50c625678..86c9d7eac 100644
--- a/docs/date.html
+++ b/docs/date.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Date
dayOfYear
Gets the day of the year from a Date object.
Use new Date() and Date.prototype.getFullYear() to get the first day of the year as a Date object, subtract it from the provided date and divide with the milliseconds in each day to get the result. Use Math.floor() to appropriately round the resulting day count to an integer.
const dayOfYear = date =>
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Date
dayOfYear
Gets the day of the year from a Date object.
Use new Date() and Date.prototype.getFullYear() to get the first day of the year as a Date object, subtract it from the provided date and divide with the milliseconds in each day to get the result. Use Math.floor() to appropriately round the resulting day count to an integer.
const dayOfYear = date =>
   Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);
 
dayOfYear(new Date()); // 272
 
formatDuration
Returns the human readable format of the given number of milliseconds.
Divide ms with the appropriate values to obtain the appropriate values for day, hour, minute, second and millisecond. Use Object.entries() with Array.prototype.filter() to keep only non-zero values. Use Array.prototype.map() to create the string for each value, pluralizing appropriately. Use String.prototype.join(', ') to combine the values into a string.
const formatDuration = ms => {
diff --git a/docs/function.html b/docs/function.html
index ca48c82e0..140561c05 100644
--- a/docs/function.html
+++ b/docs/function.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Function
attempt
Attempts to invoke a function with the provided arguments, returning either the result or the caught error object.
Use a try... catch block to return either the result of the function or an appropriate error.
const attempt = (fn, ...args) => {
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Function
attempt
Attempts to invoke a function with the provided arguments, returning either the result or the caught error object.
Use a try... catch block to return either the result of the function or an appropriate error.
const attempt = (fn, ...args) => {
   try {
     return fn(...args);
   } catch (e) {
diff --git a/docs/index.html b/docs/index.html
index 34e27fa4e..aea484332 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Array
all
Returns true if the provided predicate function returns true for all elements in a collection, false otherwise.
Use Array.prototype.every() to test if all elements in the collection return true based on fn. Omit the second argument, fn, to use Boolean as a default.
const all = (arr, fn = Boolean) => arr.every(fn);
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Array
all
Returns true if the provided predicate function returns true for all elements in a collection, false otherwise.
Use Array.prototype.every() to test if all elements in the collection return true based on fn. Omit the second argument, fn, to use Boolean as a default.
const all = (arr, fn = Boolean) => arr.every(fn);
 
all([4, 2, 3], x => x > 1); // true
 all([1, 2, 3]); // true
 
allEqual
Check if all elements in an array are equal.
Use Array.prototype.every() to check if all the elements of the array are the same as the first one.
const allEqual = arr => arr.every(val => val === arr[0]);
diff --git a/docs/math.html b/docs/math.html
index 22ca4aedf..d4a8f2a38 100644
--- a/docs/math.html
+++ b/docs/math.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Math
approximatelyEqual
Checks if two numbers are approximately equal to each other.
Use Math.abs() to compare the absolute difference of the two values to epsilon. Omit the third parameter, epsilon, to use a default value of 0.001.
const approximatelyEqual = (v1, v2, epsilon = 0.001) => Math.abs(v1 - v2) < epsilon;
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Math
approximatelyEqual
Checks if two numbers are approximately equal to each other.
Use Math.abs() to compare the absolute difference of the two values to epsilon. Omit the third parameter, epsilon, to use a default value of 0.001.
const approximatelyEqual = (v1, v2, epsilon = 0.001) => Math.abs(v1 - v2) < epsilon;
 
approximatelyEqual(Math.PI / 2.0, 1.5708); // true
 
average
Returns the average of two or more numbers.
Use Array.prototype.reduce() to add each value to an accumulator, initialized with a value of 0, divide by the length of the array.
const average = (...nums) => nums.reduce((acc, val) => acc + val, 0) / nums.length;
 
average(...[1, 2, 3]); // 2
diff --git a/docs/node.html b/docs/node.html
index b5bd260a5..90f1f3c1e 100644
--- a/docs/node.html
+++ b/docs/node.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Node
atob
Decodes a string of data which has been encoded using base-64 encoding.
Create a Buffer for the given string with base-64 encoding and use Buffer.toString('binary') to return the decoded string.
const atob = str => new Buffer(str, 'base64').toString('binary');
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Node
atob
Decodes a string of data which has been encoded using base-64 encoding.
Create a Buffer for the given string with base-64 encoding and use Buffer.toString('binary') to return the decoded string.
const atob = str => new Buffer(str, 'base64').toString('binary');
 
atob('Zm9vYmFy'); // 'foobar'
 
btoa
Creates a base-64 encoded ASCII string from a String object in which each character in the string is treated as a byte of binary data.
Create a Buffer for the given string with binary encoding and use Buffer.toString('base64') to return the encoded string.
const btoa = str => new Buffer(str, 'binary').toString('base64');
 
btoa('foobar'); // 'Zm9vYmFy'
@@ -137,8 +137,38 @@ console.log<
     )
   );
 
hashNode(JSON.stringify({ a: 'a', b: [1, 2, 3, 4], foo: { c: 'bar' } })).then(console.log); // '04aa106279f5977f59f9067fa9712afc4aedc6f5862a8defc34552d8c7206393'
+
isDuplexStream
Checks if the given argument is a duplex (readable and writable) stream.
Check if the value is different from null, use typeof to check if a value is of type object and the pipe property is of type function. Additionally check if the typeof the _read, _write and _readableState, _writableState properties are function and object respectively.
const isDuplexStream = val =>
+  val !== null &&
+  typeof val === 'object' &&
+  typeof val.pipe === 'function' &&
+  typeof val.pipe === 'function' &&
+  typeof val._read === 'function' &&
+  typeof val._readableState === 'object' &&
+  typeof val._write === 'function' &&
+  typeof val._writableState === 'object';
+
const Stream = require('stream');
+isDuplexStream(new Stream.Duplex()); // true
+
isReadableStream
Checks if the given argument is a readable stream.
Check if the value is different from null, use typeof to check if the value is of type object and the pipe property is of type function. Additionally check if the typeof the _read and _readableState properties are function and object respectively.
const isReadableStream = val =>
+  val !== null &&
+  typeof val === 'object' &&
+  typeof val.pipe === 'function' &&
+  typeof val._read === 'function' &&
+  typeof val._readableState === 'object';
+
const fs = require('fs');
+isReadableStream(fs.createReadStream('test.txt')); // true
+
isStream
Checks if the given argument is a stream.
Check if the value is different from null, use typeof to check if the value is of type object and the pipe property is of type function.
const isStream = val => val !== null && typeof val === 'object' && typeof val.pipe === 'function';
+
const fs = require('fs');
+isStream(fs.createReadStream('test.txt')); // true
 
isTravisCI
Checks if the current environment is Travis CI.
Checks if the current environment has the TRAVIS and CI environment variables (reference).
const isTravisCI = () => 'TRAVIS' in process.env && 'CI' in process.env;
 
isTravisCI(); // true (if code is running on Travis CI)
+
isWritableStream
Checks if the given argument is a writable stream.
Check if the value is different from null, use typeof to check if the value is of type object and the pipe property is of type function. Additionally check if the typeof the _write and _writableState properties are function and object respectively.
const isWritableStream = val =>
+  val !== null &&
+  typeof val === 'object' &&
+  typeof val.pipe === 'function' &&
+  typeof val._write === 'function' &&
+  typeof val._writableState === 'object';
+
const fs = require('fs');
+isWritableStream(fs.createWriteStream('test.txt')); // true
 
JSONToFile
Writes a JSON object to a file.
Use fs.writeFile(), template literals and JSON.stringify() to write a json object to a .json file.
const fs = require('fs');
 const JSONToFile = (obj, filename) =>
   fs.writeFile(`${filename}.json`, JSON.stringify(obj, null, 2));
diff --git a/docs/object.html b/docs/object.html
index 66396c8e6..15f6448e7 100644
--- a/docs/object.html
+++ b/docs/object.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Object
bindAll
Binds methods of an object to the object itself, overwriting the existing method.
Use Array.prototype.forEach() to return a function that uses Function.prototype.apply() to apply the given context (obj) to fn for each function specified.
const bindAll = (obj, ...fns) =>
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Object
bindAll
Binds methods of an object to the object itself, overwriting the existing method.
Use Array.prototype.forEach() to return a function that uses Function.prototype.apply() to apply the given context (obj) to fn for each function specified.
const bindAll = (obj, ...fns) =>
   fns.forEach(
     fn => (
       (f = obj[fn]),
diff --git a/docs/string.html b/docs/string.html
index ecba2e8b4..670520bc8 100644
--- a/docs/string.html
+++ b/docs/string.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


String
byteSize
Returns the length of a string in bytes.
Convert a given string to a Blob Object and find its size.
const byteSize = str => new Blob([str]).size;
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


String
byteSize
Returns the length of a string in bytes.
Convert a given string to a Blob Object and find its size.
const byteSize = str => new Blob([str]).size;
 
byteSize('😀'); // 4
 byteSize('Hello World'); // 11
 
capitalize
Capitalizes the first letter of a string.
Use array destructuring and String.prototype.toUpperCase() to capitalize first letter, ...rest to get array of characters after first letter and then Array.prototype.join('') to make it a string again. Omit the lowerRest parameter to keep the rest of the string intact, or set it to true to convert to lowercase.
const capitalize = ([first, ...rest], lowerRest = false) =>
diff --git a/docs/type.html b/docs/type.html
index 12dcf006c..035c78ffb 100644
--- a/docs/type.html
+++ b/docs/type.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Type
getType
Returns the native type of a value.
Returns lowercased constructor name of value, "undefined" or "null" if value is undefined or null.
const getType = v =>
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Type
getType
Returns the native type of a value.
Returns lowercased constructor name of value, "undefined" or "null" if value is undefined or null.
const getType = v =>
   v === undefined ? 'undefined' : v === null ? 'null' : v.constructor.name.toLowerCase();
 
getType(new Set([1, 2, 3])); // 'set'
 
is
Checks if the provided value is of the specified type.
Ensure the value is not undefined or null using Array.prototype.includes(), and compare the constructor property on the value with type to check if the provided value is of the specified type.
const is = (type, val) => ![, null].includes(val) && val.constructor === type;
diff --git a/docs/utility.html b/docs/utility.html
index cac9c8720..b16730f0f 100644
--- a/docs/utility.html
+++ b/docs/utility.html
@@ -91,7 +91,7 @@
             },1700);
           }
         }, false);
-      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Utility
castArray
Casts the provided value as an array if it's not one.
Use Array.prototype.isArray() to determine if val is an array and return it as-is or encapsulated in an array accordingly.
const castArray = val => (Array.isArray(val) ? val : [val]);
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.


Utility
castArray
Casts the provided value as an array if it's not one.
Use Array.prototype.isArray() to determine if val is an array and return it as-is or encapsulated in an array accordingly.
const castArray = val => (Array.isArray(val) ? val : [val]);
 
castArray('foo'); // ['foo']
 castArray([1]); // [1]
 
cloneRegExp
Clones a regular expression.
Use new RegExp(), RegExp.source and RegExp.flags to clone the given regular expression.
const cloneRegExp = regExp => new RegExp(regExp.source, regExp.flags);