import the kangax compat-table data (#121, #231)

Makefile

@@ -177,6 +177,16 @@ parcel2/node_modules:
 scripts/node_modules:
 	cd scripts && npm ci
 
+################################################################################
+# This downloads the kangax compat-table and generates browser support mappings
+
+github/compat-table:
+	mkdir -p github/compat-table
+	git clone --depth 1 https://github.com/kangax/compat-table.git github/compat-table
+
+compat-table: | github/compat-table
+	node scripts/compat-table.js
+
 ################################################################################
 # This runs the test262 official JavaScript test suite through esbuild
 

internal/compat/table.go

@@ -0,0 +1,153 @@
+// This file was automatically generated by "compat-table.js"
+
+package compat
+
+type Engine uint8
+
+const (
+	Android Engine = iota
+	Chrome
+	Edge
+	Firefox
+	Ios
+	Node
+	Safari
+)
+
+type Feature uint8
+
+const (
+	Async Feature = iota
+	AsyncIter
+	BigInt
+	ClassField
+	ClassPrivateField
+	ClassPrivateMethod
+	ClassPrivateStaticField
+	ClassPrivateStaticMethod
+	ClassStaticField
+	ExponentOperator
+	Hashbang
+	LogicalAssignment
+	NestedRestBinding
+	NullishCoalescing
+	ObjectRestSpread
+	OptionalCatchBinding
+	OptionalChain
+)
+
+var Table = map[Feature]map[Engine]float32{
+	Async: map[Engine]float32{
+		Chrome:  55,
+		Edge:    15,
+		Firefox: 52,
+		Ios:     10.3,
+		Node:    7.6,
+		Safari:  10.1,
+	},
+	AsyncIter: map[Engine]float32{
+		Chrome:  63,
+		Edge:    79,
+		Firefox: 57,
+		Ios:     12,
+		Node:    10,
+		Safari:  12,
+	},
+	BigInt: map[Engine]float32{
+		Chrome:  67,
+		Edge:    79,
+		Firefox: 68,
+		Node:    10.4,
+		Safari:  14,
+	},
+	ClassField: map[Engine]float32{
+		Chrome:  72,
+		Edge:    79,
+		Firefox: 69,
+		Node:    12,
+		Safari:  14,
+	},
+	ClassPrivateField: map[Engine]float32{
+		Chrome: 74,
+		Edge:   79,
+		Node:   12,
+	},
+	ClassPrivateMethod: map[Engine]float32{
+		Chrome: 84,
+	},
+	ClassPrivateStaticField: map[Engine]float32{
+		Chrome: 74,
+		Edge:   79,
+		Node:   12,
+	},
+	ClassPrivateStaticMethod: map[Engine]float32{
+		Chrome: 84,
+	},
+	ClassStaticField: map[Engine]float32{
+		Chrome:  72,
+		Edge:    79,
+		Firefox: 75,
+		Node:    12,
+	},
+	ExponentOperator: map[Engine]float32{
+		Chrome:  52,
+		Edge:    14,
+		Firefox: 52,
+		Ios:     10.3,
+		Node:    7,
+		Safari:  10.1,
+	},
+	Hashbang: map[Engine]float32{
+		Chrome:  74,
+		Edge:    79,
+		Firefox: 67,
+		Ios:     13.4,
+		Node:    12,
+		Safari:  13.1,
+	},
+	LogicalAssignment: map[Engine]float32{
+		Chrome:  85,
+		Firefox: 79,
+		Safari:  14,
+	},
+	NestedRestBinding: map[Engine]float32{
+		Chrome:  49,
+		Edge:    14,
+		Firefox: 47,
+		Ios:     10.3,
+		Node:    6,
+		Safari:  10.1,
+	},
+	NullishCoalescing: map[Engine]float32{
+		Chrome:  80,
+		Edge:    80,
+		Firefox: 72,
+		Ios:     13.4,
+		Node:    14,
+		Safari:  13.1,
+	},
+	ObjectRestSpread: map[Engine]float32{
+		Chrome:  60,
+		Edge:    79,
+		Firefox: 55,
+		Ios:     11.3,
+		Node:    8.1,
+		Safari:  11.1,
+	},
+	OptionalCatchBinding: map[Engine]float32{
+		Chrome:  66,
+		Edge:    79,
+		Firefox: 58,
+		Ios:     11.3,
+		Node:    10,
+		Safari:  11.1,
+	},
+	OptionalChain: map[Engine]float32{
+		Chrome:  80,
+		Edge:    80,
+		Firefox: 74,
+		Ios:     13.4,
+		Node:    14,
+		Safari:  13.1,
+	},
+}

scripts/compat-table.js

@@ -0,0 +1,132 @@
+// Run this using "make compat-table"
+const fs = require('fs')
+const path = require('path')
+const stage1to3 = require('../github/compat-table/data-esnext')
+const stage4 = require('../github/compat-table/data-es2016plus')
+const environments = require('../github/compat-table/environments.json')
+const interpolateAllResults = require('../github/compat-table/build-utils/interpolate-all-results')
+
+interpolateAllResults(stage1to3.tests, environments)
+interpolateAllResults(stage4.tests, environments)
+
+const features = {
+  'exponentiation (**) operator': { target: 'ExponentOperator' },
+  'nested rest destructuring, declarations': { target: 'NestedRestBinding' },
+  'nested rest destructuring, parameters': { target: 'NestedRestBinding' },
+  'async functions': { target: 'Async' },
+  'object rest/spread properties': { target: 'ObjectRestSpread' },
+  'Asynchronous Iterators': { target: 'AsyncIter' },
+  'optional catch binding': { target: 'OptionalCatchBinding' },
+  'BigInt: basic functionality': { target: 'BigInt' },
+  'optional chaining operator (?.)': { target: 'OptionalChain' },
+  'nullish coalescing operator (??)': { target: 'NullishCoalescing' },
+  'Logical Assignment': { target: 'LogicalAssignment' },
+  'Hashbang Grammar': { target: 'Hashbang' },
+
+  // Public fields
+  'instance class fields: public instance class fields': { target: 'ClassField' },
+  'instance class fields: computed instance class fields': { target: 'ClassField' },
+  'static class fields: public static class fields': { target: 'ClassStaticField' },
+  'static class fields: computed static class fields': { target: 'ClassStaticField' },
+
+  // Private fields
+  'instance class fields: private instance class fields basic support': { target: 'ClassPrivateField' },
+  'instance class fields: private instance class fields initializers': { target: 'ClassPrivateField' },
+  'instance class fields: optional private instance class fields access': { target: 'ClassPrivateField' },
+  'instance class fields: optional deep private instance class fields access': { target: 'ClassPrivateField' },
+  'static class fields: private static class fields': { target: 'ClassPrivateStaticField' },
+
+  // Private methods
+  'private class methods: private instance methods': { target: 'ClassPrivateMethod' },
+  'private class methods: private accessor properties': { target: 'ClassPrivateMethod' },
+  'private class methods: private static methods': { target: 'ClassPrivateStaticMethod' },
+  'private class methods: private static accessor properties': { target: 'ClassPrivateStaticMethod' },
+}
+
+const versions = {}
+const engines = [
+  'android',
+  'chrome',
+  'edge',
+  'firefox',
+  'ios',
+  'node',
+  'safari',
+]
+
+function mergeVersions(target, res) {
+  const map = versions[target] || (versions[target] = {})
+  for (const key in res) {
+    if (res[key] === true) {
+      const engine = /^[a-z]*/.exec(key)[0]
+      if (engines.indexOf(engine) >= 0) {
+        const version = +key.slice(engine.length).replace('_', '.')
+        map[engine] = Math.min(version, map[engine] || Infinity)
+      }
+    }
+  }
+}
+
+for (const test of stage4.tests.concat(stage1to3.tests)) {
+  const feature = features[test.name]
+  if (feature) {
+    feature.found = true
+    if (test.subtests) {
+      for (const subtest of test.subtests) {
+        mergeVersions(feature.target, subtest.res)
+      }
+    } else {
+      mergeVersions(feature.target, test.res)
+    }
+  } else if (test.subtests) {
+    for (const subtest of test.subtests) {
+      const feature = features[`${test.name}: ${subtest.name}`]
+      if (feature) {
+        feature.found = true
+        mergeVersions(feature.target, subtest.res)
+      }
+    }
+  }
+}
+
+for (const feature in features) {
+  if (!features[feature].found) {
+    throw new Error(`Did not find ${feature}`)
+  }
+}
+
+function upperFirstLetter(text) {
+  return text[0].toUpperCase() + text.slice(1)
+}
+
+function writeInnerMap(obj) {
+  const keys = Object.keys(obj).sort()
+  const maxLength = keys.reduce((a, b) => Math.max(a, b.length + 1), 0)
+  return keys.map(x => `\t\t${(upperFirstLetter(x) + ':').padEnd(maxLength)} ${obj[x]},`).join('\n')
+}
+
+fs.writeFileSync(__dirname + '/../internal/compat/table.go',
+  `// This file was automatically generated by "${path.basename(__filename)}"
+
+package compat
+
+type Engine uint8
+
+const (
+${engines.map((x, i) => `\t${upperFirstLetter(x)}${i ? '' : ' Engine = iota'}`).join('\n')}
+)
+
+type Feature uint8
+
+const (
+${Object.keys(versions).sort().map((x, i) => `\t${x}${i ? '' : ' Feature = iota'}`).join('\n')}
+)
+
+var Table = map[Feature]map[Engine]float32{
+${Object.keys(versions).sort().map(x => `\t${x}: map[Engine]float32{
+${writeInnerMap(versions[x])}
+\t},`).join('\n')}
+}
+`)
+
+// console.log(versions)