In-place JS environment

Summary:
This change restructures the package to try to remove the JS build step from the inner loop. Instead, we have a single `src` directory that we babel transform when using, then apply the same transform inline during prepublish.

At the end, we will be publishing a source directory with Babel transformed TS, JS, and TS declarations.

We do a little spring cleaning when doing this. Fixing up some of the folder/file conventions, and removing the non-export-map fallbacks.

We cannot remove the need for a native build.

Reviewed By: yungsters

Differential Revision: D45682153

fbshipit-source-id: ea2dd75c2dd6e3529b1ef6cf6ac6a64a270049a4

javascript/src/wrapAsm.js

@@ -0,0 +1,151 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+const CONSTANTS = require('./generated/YGEnums');
+
+module.exports = lib => {
+  function patch(prototype, name, fn) {
+    const original = prototype[name];
+
+    prototype[name] = function (...args) {
+      return fn.call(this, original, ...args);
+    };
+  }
+
+  for (const fnName of [
+    'setPosition',
+    'setMargin',
+    'setFlexBasis',
+    'setWidth',
+    'setHeight',
+    'setMinWidth',
+    'setMinHeight',
+    'setMaxWidth',
+    'setMaxHeight',
+    'setPadding',
+  ]) {
+    const methods = {
+      [CONSTANTS.UNIT_POINT]: lib.Node.prototype[fnName],
+      [CONSTANTS.UNIT_PERCENT]: lib.Node.prototype[`${fnName}Percent`],
+      [CONSTANTS.UNIT_AUTO]: lib.Node.prototype[`${fnName}Auto`],
+    };
+
+    patch(lib.Node.prototype, fnName, function (original, ...args) {
+      // We patch all these functions to add support for the following calls:
+      // .setWidth(100) / .setWidth("100%") / .setWidth(.getWidth()) / .setWidth("auto")
+
+      const value = args.pop();
+      let unit, asNumber;
+
+      if (value === 'auto') {
+        unit = CONSTANTS.UNIT_AUTO;
+        asNumber = undefined;
+      } else if (typeof value === 'object') {
+        unit = value.unit;
+        asNumber = value.valueOf();
+      } else {
+        unit =
+          typeof value === 'string' && value.endsWith('%')
+            ? CONSTANTS.UNIT_PERCENT
+            : CONSTANTS.UNIT_POINT;
+        asNumber = parseFloat(value);
+        if (!Number.isNaN(value) && Number.isNaN(asNumber)) {
+          throw new Error(`Invalid value ${value} for ${fnName}`);
+        }
+      }
+
+      if (!methods[unit])
+        throw new Error(
+          `Failed to execute "${fnName}": Unsupported unit '${value}'`,
+        );
+
+      if (asNumber !== undefined) {
+        return methods[unit].call(this, ...args, asNumber);
+      } else {
+        return methods[unit].call(this, ...args);
+      }
+    });
+  }
+
+  function wrapMeasureFunction(measureFunction) {
+    return lib.MeasureCallback.implement({
+      measure: (...args) => {
+        const {width, height} = measureFunction(...args);
+        return {
+          width: width ?? NaN,
+          height: height ?? NaN,
+        };
+      },
+    });
+  }
+
+  patch(lib.Node.prototype, 'setMeasureFunc', function (original, measureFunc) {
+    // This patch is just a convenience patch, since it helps write more
+    // idiomatic source code (such as .setMeasureFunc(null))
+    if (measureFunc) {
+      return original.call(this, wrapMeasureFunction(measureFunc));
+    } else {
+      return this.unsetMeasureFunc();
+    }
+  });
+
+  function wrapDirtiedFunc(dirtiedFunction) {
+    return lib.DirtiedCallback.implement({dirtied: dirtiedFunction});
+  }
+
+  patch(lib.Node.prototype, 'setDirtiedFunc', function (original, dirtiedFunc) {
+    original.call(this, wrapDirtiedFunc(dirtiedFunc));
+  });
+
+  patch(lib.Config.prototype, 'free', function () {
+    // Since we handle the memory allocation ourselves (via lib.Config.create),
+    // we also need to handle the deallocation
+    lib.Config.destroy(this);
+  });
+
+  patch(lib.Node, 'create', (_, config) => {
+    // We decide the constructor we want to call depending on the parameters
+    return config
+      ? lib.Node.createWithConfig(config)
+      : lib.Node.createDefault();
+  });
+
+  patch(lib.Node.prototype, 'free', function () {
+    // Since we handle the memory allocation ourselves (via lib.Node.create),
+    // we also need to handle the deallocation
+    lib.Node.destroy(this);
+  });
+
+  patch(lib.Node.prototype, 'freeRecursive', function () {
+    for (let t = 0, T = this.getChildCount(); t < T; ++t) {
+      this.getChild(0).freeRecursive();
+    }
+    this.free();
+  });
+
+  patch(
+    lib.Node.prototype,
+    'calculateLayout',
+    function (
+      original,
+      width = NaN,
+      height = NaN,
+      direction = CONSTANTS.DIRECTION_LTR,
+    ) {
+      // Just a small patch to add support for the function default parameters
+      return original.call(this, width, height, direction);
+    },
+  );
+
+  return {
+    Config: lib.Config,
+    Node: lib.Node,
+    ...CONSTANTS,
+  };
+};