add linting (and some initial fixes)

1 files changed, 38 insertions, 0 deletions

diff --git a/node_modules/code-excerpt/index.js b/node_modules/code-excerpt/index.js
new file mode 100644
index 000000000..f9a2d51b3
--- /dev/null
+++ b/node_modules/code-excerpt/index.js
@@ -0,0 +1,38 @@
+'use strict';
+
+const tabsToSpaces = require('convert-to-spaces');
+
+const generateLineNumbers = (line, around) => {
+	const lineNumbers = [];
+
+	const min = line - around;
+	const max = line + around;
+
+	for (let lineNumber = min; lineNumber <= max; lineNumber++) {
+		lineNumbers.push(lineNumber);
+	}
+
+	return lineNumbers;
+};
+
+module.exports = (source, line, options) => {
+	if (typeof source !== 'string') {
+		throw new TypeError('Source code is missing.');
+	}
+
+	if (!line || line < 1) {
+		throw new TypeError('Line number must start from `1`.');
+	}
+
+	source = tabsToSpaces(source).split('\n');
+
+	if (line > source.length) {
+		return null;
+	}
+
+	options = Object.assign({around: 3}, options);
+
+	return generateLineNumbers(line, options.around)
+		.filter(line => source[line - 1] !== undefined)
+		.map(line => ({line, value: source[line - 1]}));
+};