Generate comparative gas repports on PR (#3532)

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

scripts/checks/compareGasReports.js

@@ -0,0 +1,189 @@
+#!/usr/bin/env node
+
+const fs = require('fs');
+const chalk = require('chalk');
+const { argv } = require('yargs')
+  .env()
+  .options({
+    style: {
+      type: 'string',
+      choices: [ 'shell', 'markdown' ],
+      default: 'shell',
+    },
+  });
+
+// Deduce base tx cost from the percentage denominator
+const BASE_TX_COST = 21000;
+
+// Utilities
+function sum (...args) {
+  return args.reduce((a, b) => a + b, 0);
+}
+
+function average (...args) {
+  return sum(...args) / args.length;
+}
+
+function variation (current, previous) {
+  return {
+    value: current,
+    delta: current - previous,
+    prcnt: 100 * (current - previous) / (previous - BASE_TX_COST),
+  };
+}
+
+// Report class
+class Report {
+  // Read report file
+  static load (filepath) {
+    return JSON.parse(fs.readFileSync(filepath, 'utf8'));
+  }
+
+  // Compare two reports
+  static compare (update, ref, opts = { hideEqual: true }) {
+    if (JSON.stringify(update.config.metadata) !== JSON.stringify(ref.config.metadata)) {
+      throw new Error('Reports produced with non matching metadata');
+    }
+    return Object.keys(update.info.methods)
+      .filter(key => ref.info.methods[key])
+      .filter(key => update.info.methods[key].numberOfCalls > 0)
+      .filter(key => update.info.methods[key].numberOfCalls === ref.info.methods[key].numberOfCalls)
+      .map(key => ({
+        contract: ref.info.methods[key].contract,
+        method: ref.info.methods[key].fnSig,
+        min: variation(...[update, ref].map(x => ~~Math.min(...x.info.methods[key].gasData))),
+        max: variation(...[update, ref].map(x => ~~Math.max(...x.info.methods[key].gasData))),
+        avg: variation(...[update, ref].map(x => ~~average(...x.info.methods[key].gasData))),
+      }))
+      .filter(row => !opts.hideEqual || (row.min.delta && row.max.delta && row.avg.delta))
+      .sort((a, b) => `${a.contract}:${a.method}` < `${b.contract}:${b.method}` ? -1 : 1);
+  }
+}
+
+// Display
+function center (text, length) {
+  return text.padStart((text.length + length) / 2).padEnd(length);
+}
+
+function plusSign (num) {
+  return num > 0 ? '+' : '';
+}
+
+function formatCellShell (cell) {
+  const format = chalk[cell.delta > 0 ? 'red' : cell.delta < 0 ? 'green' : 'reset'];
+  return [
+    format((isNaN(cell.value) ? '-' : cell.value.toString()).padStart(8)),
+    format((isNaN(cell.delta) ? '-' : plusSign(cell.delta) + cell.delta.toString()).padStart(8)),
+    format((isNaN(cell.prcnt) ? '-' : plusSign(cell.prcnt) + cell.prcnt.toFixed(2) + '%').padStart(8)),
+  ];
+}
+
+function formatCmpShell (rows) {
+  const contractLength = Math.max(8, ...rows.map(({ contract }) => contract.length));
+  const methodLength = Math.max(7, ...rows.map(({ method }) => method.length));
+
+  const COLS = [
+    { txt: '', length: 0 },
+    { txt: 'Contract', length: contractLength },
+    { txt: 'Method', length: methodLength },
+    { txt: 'Min', length: 30 },
+    { txt: 'Avg', length: 30 },
+    { txt: 'Max', length: 30 },
+    { txt: '', length: 0 },
+  ];
+  const HEADER = COLS.map(entry => chalk.bold(center(entry.txt, entry.length || 0))).join(' | ').trim();
+  const SEPARATOR = COLS.map(({ length }) => length > 0 ? '-'.repeat(length + 2) : '').join('|').trim();
+
+  return [
+    '',
+    HEADER,
+    ...rows.map(entry => [
+      '',
+      chalk.grey(entry.contract.padEnd(contractLength)),
+      entry.method.padEnd(methodLength),
+      ...formatCellShell(entry.min),
+      ...formatCellShell(entry.avg),
+      ...formatCellShell(entry.max),
+      '',
+    ].join(' | ').trim()),
+    '',
+  ].join(`\n${SEPARATOR}\n`).trim();
+}
+
+function alignPattern (align) {
+  switch (align) {
+  case 'left':
+  case undefined:
+    return ':-';
+  case 'right':
+    return '-:';
+  case 'center':
+    return ':-:';
+  }
+}
+
+function trend (value) {
+  return value > 0
+    ? ':x:'
+    : value < 0
+      ? ':heavy_check_mark:'
+      : ':heavy_minus_sign:';
+}
+
+function formatCellMarkdown (cell) {
+  return [
+    (isNaN(cell.value) ? '-' : cell.value.toString()),
+    (isNaN(cell.delta) ? '-' : plusSign(cell.delta) + cell.delta.toString()),
+    (isNaN(cell.prcnt) ? '-' : plusSign(cell.prcnt) + cell.prcnt.toFixed(2) + '%') + trend(cell.delta),
+  ];
+}
+
+function formatCmpMarkdown (rows) {
+  const COLS = [
+    { txt: '' },
+    { txt: 'Contract', align: 'left' },
+    { txt: 'Method', align: 'left' },
+    { txt: 'Min', align: 'right' },
+    { txt: '(+/-)', align: 'right' },
+    { txt: '%', align: 'right' },
+    { txt: 'Avg', align: 'right' },
+    { txt: '(+/-)', align: 'right' },
+    { txt: '%', align: 'right' },
+    { txt: 'Max', align: 'right' },
+    { txt: '(+/-)', align: 'right' },
+    { txt: '%', align: 'right' },
+    { txt: '' },
+  ];
+  const HEADER = COLS.map(entry => entry.txt).join(' | ').trim();
+  const SEPARATOR = COLS.map(entry => entry.txt ? alignPattern(entry.align) : '').join('|').trim();
+
+  return [
+    '# Changes to gas costs',
+    '',
+    HEADER,
+    SEPARATOR,
+    rows.map(entry => [
+      '',
+      entry.contract,
+      entry.method,
+      ...formatCellMarkdown(entry.min),
+      ...formatCellMarkdown(entry.avg),
+      ...formatCellMarkdown(entry.max),
+      '',
+    ].join(' | ').trim()).join('\n'),
+    '',
+  ].join('\n').trim();
+}
+
+// MAIN
+const report = Report.compare(Report.load(argv._[0]), Report.load(argv._[1]));
+
+switch (argv.style) {
+case 'markdown':
+  console.log(formatCmpMarkdown(report));
+  break;
+case 'shell':
+default:
+  console.log(formatCmpShell(report));
+  break;
+}