array-group-str-omit-num-char

Groups array of strings by omitting number characters

Install

npm i array-group-str-omit-num-char

// consume as CommonJS require():
const group = require("array-group-str-omit-num-char");
// or as ES Module:
import group from "array-group-str-omit-num-char";

Here's what you'll get:

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Table of Contents

• Install
• Idea
• API
• Contributing
• Licence

Idea

Take an array of strings, group those which differ only by a certain number.

For example, consider this array atomic CSS class names coming from some report (for example, email-comb output object's key deletedFromHead):

[
  "wbr425-padding-top-1",
  "wbr425-padding-top-2",
  "main-title",
  "wbr425-padding-top-3"
];

In real life, you could have for example, wbr425-padding-top-* would be shorter and go up to 500 and there were, let's say, 20 other groups like it.

This npm library groups strings, in this case producing:

{
  "wbr425-padding-top-*": 3,
  "main-title": 1
}

Notice the "425" in wbr425 was not replaced with wildcard because it was constant on all strings that were grouped. This feature, retaining constant digits, was the reason why we got into hassle producing this library.

You see, the quickest, alternative (gung-ho) algorithm is to replace all digits with "*" and filter the unique values, but "425" in wbr425 would be lost. That's why we need this library.

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API

The main function is exported as default, so you can name it whatever you want when you import/require. For example, instead of "group", you could name the main function "brambles": const brambles = require("array-group-str-omit-num-char");. But let's consider you chose default name, "group".

The API of this library is the following:

group(
  sourceArray, // input array of strings
  opts // an optional options array
);

In other words, that variable you imported, "group" (or "brambles" or whatever) is a function which consumes two input arguments.

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API - Input

By the way, none of the input arguments are mutated.

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An Optional Options Object

Type: object - an Optional Options Object.

Here are all defaults in one place for copying:

{
  wildcard: "*",
  dedupePlease: true
}

To explicitly mark the refusal to set custom Optional Options, it can be also passed as a null or undefined value. In that case, defaults will be set.

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API - Output

An empty array input will give output of a empty plain object. A non-empty array (with at least one string inside) will yield a plain object: strings will be grouped and put as keys, they count will be put as integer values.

For example:

console.log(group(["a1-1", "a2-2", "b3-3", "c4-4"]));
// {
//   "a*-*": 2,
//   "b3-3": 1,
//   "c4-4": 1
// }

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Contributing

• If you see an error, raise an issue.
• If you want a new feature but can't code it up yourself, also raise an issue. Let's discuss it.
• If you tried to use this package, but something didn't work out, also raise an issue. We'll try to help.
• If you want to contribute some code, fork the monorepo via BitBucket, then write code, then file a pull request via BitBucket. We'll merge it in and release.

In monorepo, npm libraries are located in packages/ folder. Inside, the source code is located either in src/ folder (normal npm library) or in the root, cli.js (if it's a command line application).

The npm script "dev", the "dev": "rollup -c --dev --silent" builds the development version retaining all console.logs with row numbers. It's handy to have js-row-num-cli installed globally so you can automatically update the row numbers on all console.logs.

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Licence

MIT License

Copyright (c) 2015-2019 Roy Revelt and other contributors