From aee673ac4716ea548292554d7834570add2cad37 Mon Sep 17 00:00:00 2001
From: Justin Ridgewell <justin@ridgewell.name>
Date: Thu, 18 Mar 2021 23:51:57 -0400
Subject: [PATCH 1/2] Remove lodash from babel-compat-data

---
 packages/babel-compat-data/package.json       |  3 +-
 .../scripts/utils-build-data.js               | 28 +++++++++++++------
 yarn.lock                                     |  1 -
 3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/packages/babel-compat-data/package.json b/packages/babel-compat-data/package.json
index 890f92523384..727318da889a 100644
--- a/packages/babel-compat-data/package.json
+++ b/packages/babel-compat-data/package.json
@@ -31,7 +31,6 @@
   "devDependencies": {
     "@mdn/browser-compat-data": "^3.1.1",
     "core-js-compat": "^3.9.0",
-    "electron-to-chromium": "1.3.672",
-    "lodash": "^4.17.19"
+    "electron-to-chromium": "1.3.672"
   }
 }
diff --git a/packages/babel-compat-data/scripts/utils-build-data.js b/packages/babel-compat-data/scripts/utils-build-data.js
index e8a21f4f27fd..a6cf380e6b82 100644
--- a/packages/babel-compat-data/scripts/utils-build-data.js
+++ b/packages/babel-compat-data/scripts/utils-build-data.js
@@ -1,9 +1,6 @@
 "use strict";
 
 const fs = require("fs");
-const flatMap = require("lodash/flatMap");
-const mapValues = require("lodash/mapValues");
-const findLastIndex = require("lodash/findLastIndex");
 const { addElectronSupportFromChromium } = require("./chromium-to-electron");
 
 const envs = require("../build/compat-table/environments");
@@ -35,6 +32,13 @@ exports.environments = [
   "samsung",
 ];
 
+function flatMap(array, cb) {
+  if (array.flatMap) return array.flatMap(cb);
+  return array.reduce((flattened, value) => {
+    return flattened.concat(value);
+  }, []);
+}
+
 const compatibilityTests = flatMap(compatSources, data =>
   flatMap(data.tests, test => {
     if (!test.subtests) return test;
@@ -63,13 +67,19 @@ exports.getLowestImplementedVersion = (
   });
 
   const envTests = tests.map(({ res }) => {
-    const lastNotImplemented = findLastIndex(
-      envsVersions[env],
+    const versions = envsVersions[env];
+    let i = versions.length - 1;
+
+    // Find the last not-implemented version
+    for (; i >= 0; i--) {
+      const { id } = versions[i];
       // Babel assumes strict mode
-      ({ id }) => !(res[id] === true || res[id] === "strict")
-    );
+      if (res[id] !== true && res[id] !== "strict") {
+        break;
+      }
+    }
 
-    return envsVersions[env][lastNotImplemented + 1];
+    return envsVersions[env][i + 1];
   });
 
   if (envTests.length === 0 || envTests.some(t => !t)) return null;
@@ -85,7 +95,7 @@ exports.getLowestImplementedVersion = (
 };
 
 exports.generateData = (environments, features) => {
-  return mapValues(features, options => {
+  return Object.values(features).map(options => {
     if (!options.features) {
       options = {
         features: [options],
diff --git a/yarn.lock b/yarn.lock
index 3760fee11bb2..8d83f07ca3c8 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -146,7 +146,6 @@ __metadata:
     "@mdn/browser-compat-data": ^3.1.1
     core-js-compat: ^3.9.0
     electron-to-chromium: 1.3.672
-    lodash: ^4.17.19
   languageName: unknown
   linkType: soft
 

From 02fbf1b7b1c4b2c4c4ac6fb229bc40ffad5d6253 Mon Sep 17 00:00:00 2001
From: Justin Ridgewell <justin@ridgewell.name>
Date: Fri, 19 Mar 2021 18:21:53 -0400
Subject: [PATCH 2/2] Remove flatMap poorlyfill.

---
 .../babel-compat-data/scripts/utils-build-data.js     | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/packages/babel-compat-data/scripts/utils-build-data.js b/packages/babel-compat-data/scripts/utils-build-data.js
index a6cf380e6b82..05bd79dc062a 100644
--- a/packages/babel-compat-data/scripts/utils-build-data.js
+++ b/packages/babel-compat-data/scripts/utils-build-data.js
@@ -32,15 +32,8 @@ exports.environments = [
   "samsung",
 ];
 
-function flatMap(array, cb) {
-  if (array.flatMap) return array.flatMap(cb);
-  return array.reduce((flattened, value) => {
-    return flattened.concat(value);
-  }, []);
-}
-
-const compatibilityTests = flatMap(compatSources, data =>
-  flatMap(data.tests, test => {
+const compatibilityTests = compatSources.flatMap(data =>
+  data.tests.flatMap(test => {
     if (!test.subtests) return test;
 
     return test.subtests.map(subtest =>