trim factory bundle: skip plot_api/index.js, replace events package

Two optimizations to the `createPlotly()` factory:

1. Import `plot_api/plot_api.js` directly instead of `plot_api/index.js`,
   avoiding transitive imports of `to_image.js`, `validate.js`,
   `template_api.js`, and `snapshot/download.js` (-17 KB min)

2. Replace Node.js `events` package (15 KB) with inline MiniEmitter
   (~50 lines) in `lib/events.js`. Only `on`/`once`/`emit`/
   `removeListener`/`removeAllListeners` are used. (-5 KB min)

Factory: 741 KB min (was 763 KB, -22 KB / -2.9%)
vs upstream basic: -33% (was -30%)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ryan-williams

perf/bundle-compare/thresholds.json

@@ -1,13 +1,13 @@
 {
     "upstream_full__min_": 4831947,
     "upstream_basic__min_": 1114816,
-    "fork_full__min_": 4808668,
-    "fork_basic__min_": 1095031,
-    "fork_minimal__min_": 987325,
-    "fork_lite__min_": 847320,
+    "fork_full__min_": 4809524,
+    "fork_basic__min_": 1095887,
+    "fork_minimal__min_": 988182,
+    "fork_lite__min_": 848177,
     "app___upstream_basic": 1115573,
-    "app___fork_basic": 1095179,
-    "app___fork_lite": 847412,
-    "fork_factory__min_": 781250,
-    "app___fork_factory": 781250
+    "app___fork_basic": 1096035,
+    "app___fork_lite": 848269,
+    "fork_factory__min_": 758490,
+    "app___fork_factory": 758490
 }

perf/thresholds.json

@@ -1,19 +1,19 @@
 {
     "bundleSize": {
         "lite": {
-            "expected_bytes": 1801579
+            "expected_bytes": 1803169
         },
         "lite-min": {
             "expected_bytes": 916326
         },
         "minimal": {
-            "expected_bytes": 2124345
+            "expected_bytes": 2125952
         },
         "minimal-min": {
             "expected_bytes": 1076875
         },
         "basic": {
-            "expected_bytes": 2429429
+            "expected_bytes": 2431036
         },
         "basic-min": {
             "expected_bytes": 1185641

src/core-factory.js

@@ -20,7 +20,9 @@ import './lib/d3-compat.js';
 import 'd3-transition';
 import 'native-promise-only';
 import Registry from './registry.js';
-import plotApi from './plot_api/index.js';
+// Import plot_api.js directly (not index.js) to avoid pulling in
+// to_image, validate, template_api, snapshot/download
+import main from './plot_api/plot_api.js';
 import FxModule from './components/fx/index.js';
 import PlotsModule from './plots/plots.js';
 import { version } from './version.js';
@@ -34,6 +36,14 @@ import modebar from './components/modebar/index.js';
 import localeEn from './locale-en.js';
 import localeEnUs from './locale-en-us.js';
 
+// API methods needed for runtime (excludes toImage, validate, etc.)
+var apiMethodNames = [
+    'newPlot', 'react', 'restyle', 'relayout', 'redraw', 'update',
+    'extendTraces', 'prependTraces', 'addTraces', 'deleteTraces', 'moveTraces',
+    'purge', 'addFrames', 'deleteFrames', 'animate', 'setPlotConfig',
+    '_doPlot', '_guiRestyle', '_guiRelayout', '_guiUpdate', '_storeDirectGUIEdit',
+];
+
 export function createPlotly({ traces = [], components = [], Icons, Snapshot, PlotSchema } = {}) {
     var register = Registry.register;
     var Plotly = { version, register };
@@ -42,11 +52,11 @@ export function createPlotly({ traces = [], components = [], Icons, Snapshot, Pl
     if(PlotSchema) Plotly.PlotSchema = PlotSchema;
 
     // Register API methods
-    var methodNames = Object.keys(plotApi);
-    for(var i = 0; i < methodNames.length; i++) {
-        var name = methodNames[i];
-        if(name.charAt(0) !== '_') Plotly[name] = plotApi[name];
-        register({ moduleType: 'apiMethod', name: name, fn: plotApi[name] });
+    for(var i = 0; i < apiMethodNames.length; i++) {
+        var name = apiMethodNames[i];
+        if(!main[name]) continue;
+        if(name.charAt(0) !== '_') Plotly[name] = main[name];
+        register({ moduleType: 'apiMethod', name: name, fn: main[name] });
     }
 
     // Register essential components (always needed)

src/lib/events.js

@@ -1,16 +1,63 @@
-import { EventEmitter } from 'events';
+// Minimal EventEmitter (replaces Node.js 'events' package, ~15 KB)
+function MiniEmitter() {
+    this._events = {};
+}
+MiniEmitter.prototype.on = function(event, fn) {
+    var handlers = this._events[event];
+    if(!handlers) this._events[event] = fn;
+    else if(typeof handlers === 'function') this._events[event] = [handlers, fn];
+    else handlers.push(fn);
+    return this;
+};
+MiniEmitter.prototype.once = function(event, fn) {
+    var self = this;
+    function wrapper() {
+        self.removeListener(event, wrapper);
+        fn.apply(this, arguments);
+    }
+    wrapper.listener = fn;
+    return this.on(event, wrapper);
+};
+MiniEmitter.prototype.removeListener = function(event, fn) {
+    var handlers = this._events[event];
+    if(!handlers) return this;
+    if(typeof handlers === 'function') {
+        if(handlers === fn || handlers.listener === fn) delete this._events[event];
+    } else {
+        for(var i = handlers.length - 1; i >= 0; i--) {
+            if(handlers[i] === fn || handlers[i].listener === fn) {
+                handlers.splice(i, 1);
+                break;
+            }
+        }
+        if(handlers.length === 0) delete this._events[event];
+        else if(handlers.length === 1) this._events[event] = handlers[0];
+    }
+    return this;
+};
+MiniEmitter.prototype.removeAllListeners = function(event) {
+    if(event) delete this._events[event];
+    else this._events = {};
+    return this;
+};
+MiniEmitter.prototype.emit = function(event, data) {
+    var handlers = this._events[event];
+    if(!handlers) return false;
+    if(typeof handlers === 'function') handlers.call(this, data);
+    else {
+        var arr = handlers.slice();
+        for(var i = 0; i < arr.length; i++) arr[i].call(this, data);
+    }
+    return true;
+};
 
 var Events = {
 
     init: function(plotObj) {
-        /*
-         * If we have already instantiated an emitter for this plot
-         * return early.
-         */
-        if(plotObj._ev instanceof EventEmitter) return plotObj;
+        if(plotObj._ev instanceof MiniEmitter) return plotObj;
 
-        var ev = new EventEmitter();
-        var internalEv = new EventEmitter();
+        var ev = new MiniEmitter();
+        var internalEv = new MiniEmitter();
 
         /*
          * Assign to plot._ev while we still live in a land