feat: Expose bar width flag. (#152)

This should have been wired up in the original PR. Not sure why this
got left disconnected like this.

Author: jdmarshall

lib/reporter/chart.js

@@ -9,18 +9,10 @@ const { analyze } = require("../utils/analyze.js");
  * @param {number} total - The maximum value in the dataset (for scaling)
  * @param {number} samples - Number of samples collected
  * @param {string} metric - The metric being displayed (opsSec or totalTime)
+ * @param {number} width - Length of the bar in characters
  * @param {string} [comment=""] - optional additional comment
- * @param {number} [length=25] - Length of the bar in characters
  */
-function drawBar(
-	label,
-	value,
-	total,
-	samples,
-	metric,
-	comment = "",
-	length = 25,
-) {
+function drawBar(label, value, total, samples, metric, width, comment = "") {
 	let percentage;
 	let displayedValue;
 	let displayedMetric;
@@ -52,15 +44,15 @@ function drawBar(
 		displayedMetric = "total time";
 	}
 
-	const ratio = length * percentage;
+	const ratio = width * percentage;
 	const filledLength = Math.floor(ratio);
 	const fraction = ratio % 1;
 	const partial = fraction >= 0.5 ? "▌" : "";
 
 	const bar =
 		"█".repeat(filledLength) +
 		partial +
-		"─".repeat(length - filledLength - partial.length);
+		"─".repeat(width - filledLength - partial.length);
 
 	const displayedSamples = `${styleText(["yellow"], samples.toString().padStart(2))} samples`;
 
@@ -99,7 +91,10 @@ function chartReport(results, options = { labelWidth: 45, printHeader: true }) {
  * @param {BenchmarkResult[]} results - Array of benchmark results
  * @param options {object} layout options
  */
-function toChart(results, options = { labelWidth: 45, printHeader: true }) {
+function toChart(
+	results,
+	options = { labelWidth: 45, printHeader: true, barWidth: 25 },
+) {
 	// Determine the primary metric and calculate max value for scaling
 	const primaryMetric =
 		results[0]?.opsSec !== undefined ? "opsSec" : "totalTime";
@@ -151,6 +146,7 @@ function toChart(results, options = { labelWidth: 45, printHeader: true }) {
 			maxValue,
 			result.histogram.samples,
 			primaryMetric,
+			options.barWidth ?? 25,
 			comment,
 		);
 	}

test/reporter.js

@@ -515,7 +515,7 @@ describe("baseline comparisons", async (t) => {
 		let output = "";
 
 		before(async () => {
-			output = toChart(results, { labelWidth: 30 });
+			output = toChart(results, {});
 		});
 
 		it("should include a summary section", () => {
@@ -532,9 +532,42 @@ describe("baseline comparisons", async (t) => {
 			assert.ok(summary.includes("slower"));
 		});
 
-		it("can set a specific column width", () => {
+		it("uses the default column width for the name", () => {
 			const summary = output.split("Summary (vs. baseline):")[1];
-			assert.ok(summary.includes("baseline-test                  ▏"));
+			assert.ok(
+				//                123456789012345678901234567890123456789012345 ▏
+				summary.includes("baseline-test                                 ▏"),
+			);
+		});
+
+		it("can adjust the display widths to suite", () => {
+			const inputs = [
+				{
+					iterations: 1635480,
+					histogram: {
+						samples: 11,
+						min: 301.5006542361793,
+						max: 313.07250487172166,
+						sampleData: [
+							301.5006542361793, 301.5593469278305, 302.8870084803949,
+							304.6617804001423, 304.71883159667146, 305.0352153017722,
+							306.6694294422758, 306.9953128406366, 309.27860394347147,
+							310.3016037436935, 313.07250487172166,
+						],
+					},
+					name: "baseline-test",
+					baseline: true,
+					opsSec: 3268352.671656186,
+					opsSecPerRun: [3268352.671656186],
+				},
+			];
+
+			output = toChart(inputs, { labelWidth: 20, barWidth: 10 });
+
+			const summary = output.split("Summary (vs. baseline):")[1];
+
+			//                          12345678901234567890 ▏1234567890 ▏
+			assert.ok(summary.includes("baseline-test        ▏██████████▕ "));
 		});
 	});
 });