initial commit

node_modules/istextorbinary/source/index.js

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+/* eslint no-use-before-define:0 */
+'use strict'
+
+// Import
+const pathUtil = require('path')
+const textExtensions = require('textextensions')
+const binaryExtensions = require('binaryextensions')
+
+/**
+ * Is Text (Synchronous)
+ * Determine whether or not a file is a text or binary file.
+ * Determined by extension checks first, then if unknown extension, will fallback on encoding detection.
+ * We do that as encoding detection cannot guarantee everything, especially for chars between utf8 and utf16
+ * @param {?string} filename - the filename for the file/buffer if available
+ * @param {?Buffer} buffer - the buffer for the file if available
+ * @returns {Error|boolean}
+ */
+function isTextSync (filename, buffer) {
+	// Prepare
+	let isText = null
+
+	// Test extensions
+	if (filename) {
+		// Extract filename
+		const parts = pathUtil.basename(filename).split('.').reverse()
+
+		// Cycle extensions
+		for (const extension of parts) {
+			if (textExtensions.indexOf(extension) !== -1) {
+				isText = true
+				break
+			}
+			if (binaryExtensions.indexOf(extension) !== -1) {
+				isText = false
+				break
+			}
+		}
+	}
+
+	// Fallback to encoding if extension check was not enough
+	if (buffer && isText === null) {
+		isText = getEncodingSync(buffer) === 'utf8'
+	}
+
+	// Return our result
+	return isText
+}
+
+/**
+ * Is Text
+ * Uses `isTextSync` behind the scenes.
+ * @param {?string} filename - forwarded to `isTextSync`
+ * @param {?Buffer} buffer - forwarded to `isTextSync`
+ * @param {Function} next - accepts arguments: (error: Error, result: Boolean)
+ * @returns {nothing}
+ */
+function isText (filename, buffer, next) {
+	const result = isTextSync(filename, buffer)
+	if (result instanceof Error) {
+		next(result)
+	}
+	else {
+		next(null, result)
+	}
+}
+
+/**
+ * Is Binary (Synchronous)
+ * Uses `isTextSync` behind the scenes.
+ * @param {?string} filename - forwarded to `isTextSync`
+ * @param {?Buffer} buffer - forwarded to `isTextSync`
+ * @returns {Error|boolean}
+ */
+function isBinarySync (filename, buffer) {
+	// Handle
+	const result = isTextSync(filename, buffer)
+	return result instanceof Error ? result : !result
+}
+
+/**
+ * Is Binary
+ * Uses `isText` behind the scenes.
+ * @param {?string} filename - forwarded to `isText`
+ * @param {?Buffer} buffer - forwarded to `isText`
+ * @param {Function} next - accepts arguments: (error: Error, result: Boolean)
+ * @returns {nothing}
+ */
+function isBinary (filename, buffer, next) {
+	// Handle
+	isText(filename, buffer, function (err, result) {
+		if (err) return next(err)
+		return next(null, !result)
+	})
+}
+
+/**
+ * Get the encoding of a buffer.
+ * We fetch a bunch chars from the start, middle and end of the buffer.
+ * We check all three, as doing only start was not enough, and doing only middle was not enough, so better safe than sorry.
+ * @param {Buffer} buffer
+ * @param {?Object} [opts]
+ * @param {?number} [opts.chunkLength = 24]
+ * @param {?number} [opts.chunkBegin = 0]
+ * @returns {Error|string} either an Error instance if something went wrong, or if successful "utf8" or "binary"
+ */
+function getEncodingSync (buffer, opts) {
+	// Prepare
+	const textEncoding = 'utf8'
+	const binaryEncoding = 'binary'
+
+	// Discover
+	if (opts == null) {
+		// Start
+		const chunkLength = 24
+		let encoding = getEncodingSync(buffer, { chunkLength })
+		if (encoding === textEncoding) {
+			// Middle
+			let chunkBegin = Math.max(0, Math.floor(buffer.length / 2) - chunkLength)
+			encoding = getEncodingSync(buffer, { chunkLength, chunkBegin })
+			if (encoding === textEncoding) {
+				// End
+				chunkBegin = Math.max(0, buffer.length - chunkLength)
+				encoding = getEncodingSync(buffer, { chunkLength, chunkBegin })
+			}
+		}
+
+		// Return
+		return encoding
+	}
+	else {
+		// Extract
+		const { chunkLength = 24, chunkBegin = 0 } = opts
+		const chunkEnd = Math.min(buffer.length, chunkBegin + chunkLength)
+		const contentChunkUTF8 = buffer.toString(textEncoding, chunkBegin, chunkEnd)
+		let encoding = textEncoding
+
+		// Detect encoding
+		for (let i = 0; i < contentChunkUTF8.length; ++i) {
+			const charCode = contentChunkUTF8.charCodeAt(i)
+			if (charCode === 65533 || charCode <= 8) {
+				// 8 and below are control characters (e.g. backspace, null, eof, etc.)
+				// 65533 is the unknown character
+				// console.log(charCode, contentChunkUTF8[i])
+				encoding = binaryEncoding
+				break
+			}
+		}
+
+		// Return
+		return encoding
+	}
+}
+
+/**
+ * Get the encoding of a buffer
+ * Uses `getEncodingSync` behind the scenes.
+ * @param {Buffer} buffer - forwarded to `getEncodingSync`
+ * @param {Object} opts - forwarded to `getEncodingSync`
+ * @param {Function} next - accepts arguments: (error: Error, result: Boolean)
+ * @returns {nothing}
+ */
+function getEncoding (buffer, opts, next) {
+	// Fetch and wrap result
+	const result = getEncodingSync(buffer, opts)
+	if (result instanceof Error) {
+		next(result)
+	}
+	else {
+		next(null, result)
+	}
+}
+
+// Export
+module.exports = { isTextSync, isText, isBinarySync, isBinary, getEncodingSync, getEncoding }