--- /dev/null
+import isNumber from 'is-number-object';
+import isString from 'is-string';
+import stringWidth from 'string-width';
+
+const alignments = [
+ 'left',
+ 'right',
+ 'center',
+];
+
+/**
+ * @param {string} subject
+ * @param {number} width
+ * @returns {string}
+ */
+const alignLeft = (subject, width) => {
+ return subject + ' '.repeat(width);
+};
+
+/**
+ * @param {string} subject
+ * @param {number} width
+ * @returns {string}
+ */
+const alignRight = (subject, width) => {
+ return ' '.repeat(width) + subject;
+};
+
+/**
+ * @param {string} subject
+ * @param {number} width
+ * @returns {string}
+ */
+const alignCenter = (subject, width) => {
+ let halfWidth;
+
+ halfWidth = width / 2;
+
+ if (width % 2 === 0) {
+ return ' '.repeat(halfWidth) + subject + ' '.repeat(halfWidth);
+ } else {
+ halfWidth = Math.floor(halfWidth);
+
+ return ' '.repeat(halfWidth) + subject + ' '.repeat(halfWidth + 1);
+ }
+};
+
+/**
+ * Pads a string to the left and/or right to position the subject
+ * text in a desired alignment within a container.
+ *
+ * @param {string} subject
+ * @param {number} containerWidth
+ * @param {string} alignment One of the valid options (left, right, center).
+ * @returns {string}
+ */
+export default (subject, containerWidth, alignment) => {
+ if (!isString(subject)) {
+ throw new TypeError('Subject parameter value must be a string.');
+ }
+
+ if (!isNumber(containerWidth)) {
+ throw new TypeError('Container width parameter value must be a number.');
+ }
+
+ const subjectWidth = stringWidth(subject);
+
+ if (subjectWidth > containerWidth) {
+ // console.log('subjectWidth', subjectWidth, 'containerWidth', containerWidth, 'subject', subject);
+
+ throw new Error('Subject parameter value width cannot be greater than the container width.');
+ }
+
+ if (!isString(alignment)) {
+ throw new TypeError('Alignment parameter value must be a string.');
+ }
+
+ if (!alignments.includes(alignment)) {
+ throw new Error('Alignment parameter value must be a known alignment parameter value (left, right, center).');
+ }
+
+ if (subjectWidth === 0) {
+ return ' '.repeat(containerWidth);
+ }
+
+ const availableWidth = containerWidth - subjectWidth;
+
+ if (alignment === 'left') {
+ return alignLeft(subject, availableWidth);
+ }
+
+ if (alignment === 'right') {
+ return alignRight(subject, availableWidth);
+ }
+
+ return alignCenter(subject, availableWidth);
+};