npm package: @pelevesque/has_required_substrings_at_indexes
Description: Checks if a string has required substrings at given indexes.
Author: Pierre-Emmanuel Lévesque
Latest version: 1.1.1

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# has_required_substrings_at_indexes

Checks if a string has required substrings at given indexes.

## Related Packages

https://github.com/pelevesque/has_prohibited_substring_at_indexes  
https://github.com/pelevesque/has_required_substrings  
https://github.com/pelevesque/has_prohibited_substring  
https://github.com/pelevesque/has_required_substrings_after_sums  
https://github.com/pelevesque/has_prohibited_substring_after_sums  

## Node Repository

https://www.npmjs.com/package/@pelevesque/has_required_substrings_at_indexes

## Installation

`npm install @pelevesque/has_required_substrings_at_indexes`

## Tests

### Standard Style & Unit Tests

`npm test`

### Unit Tests & Coverage

`npm run cover`

## Usage

### Parameters

```js
str                (required)
requiredSubstrings (required)
options            (optional) default = { allowLastSubstringToBleed = false, ignoreSubstringsOutsideString = false }
```

### Requiring

```js
const hasRequiredSubstringsAtIndexes = require('@pelevesque/has_required_substrings_at_indexes')
```

### Basic Usage

`requiredSubstrings` is an object of index -> substring pairs. `true` is returned
if all substrings are found at the correct indexes.

```js
const str = 'abcde'
const requiredSubstrings = { 0: 'f' }
const result = hasRequiredSubstringsAtIndexes(str, requiredSubstrings)
// result === false
```

```js
const str = 'abcde'
const requiredSubstrings = { 5: 'f' }
const result = hasRequiredSubstringsAtIndexes(str, requiredSubstrings)
// result === false
```

```js
const str = 'abcde'
const requiredSubstrings = { 0: 'a', 2: 'c', 4: 'a' }
const result = hasRequiredSubstringsAtIndexes(str, requiredSubstrings)
// result === false
```

```js
const str = 'abcde'
const requiredSubstrings = { 0: 'a', 2: 'c', 4: 'e' }
const result = hasRequiredSubstringsAtIndexes(str, requiredSubstrings)
// result === true
```

```js
const str = 'a man a plan a canal'
const requiredSubstrings = { 2: 'man', 8: 'plan', 15: 'canal' }
const result = hasRequiredSubstringsAtIndexes(str, requiredSubstrings)
// result === true
```

### Options

#### allowLastSubstringToBleed

The `allowLastSubstringToBleed` option is `false` by default. It it used when you want
to allow the last substring to be incomplete if the string is too short.
In the following example, the last substring `canal` starts at the correct index,
but remains incomplete since the string ends. Normally this would return `false`.
With `allowLastSubstringToBleed` set to `true`, it returns `true`.

```js
const str = 'a man a plan a c'
const requiredSubstrings = { 2: 'man', 8: 'plan', 15: 'canal' }
const allowLastSubstringToBleed = true
const result = hasRequiredSubstringsAtIndexes(str, requiredSubstrings, {
  allowLastSubstringToBleed: allowLastSubstringToBleed
})
// result === true
```

#### ignoreIndexesOutsideString

The `ignoreIndexesOutsideString` option is `false` by default. When set to `true`,
required substring indexes that fall outside the string length will be ignored.

```js
const str = 'abcde'
const requiredSubstrings = { 5: 'f' }
const ignoreIndexesOutsideString = true
const result = hasRequiredSubstringsAtIndexes(str, requiredSubstrings, {
  ignoreIndexesOutsideString: ignoreIndexesOutsideString
})
// result === true
```