1 files changed, 39 insertions, 0 deletions
diff --git a/thirdparty/preact/config/codemod-const.js b/thirdparty/preact/config/codemod-const.js
new file mode 100644
index 000000000..4bffd9add
--- /dev/null
+++ b/thirdparty/preact/config/codemod-const.js
@@ -0,0 +1,39 @@
+/* eslint no-console:0 */
+
+/** Find constants (identified by ALL_CAPS_DECLARATIONS), and inline them globally.
+ *	This is safe because Preact *only* uses global constants.
+ */
+export default (file, api) => {
+	let j = api.jscodeshift,
+		code = j(file.source),
+		constants = {},
+		found = 0;
+
+	code.find(j.VariableDeclaration)
+		.filter( decl => {
+			for (let i=decl.value.declarations.length; i--; ) {
+				let node = decl.value.declarations[i],
+					name = node.id && node.id.name,
+					init = node.init;
+				if (name && init && name.match(/^[A-Z0-9_$]+$/g)) {
+					if (init.type==='Literal') {
+						console.log(`Inlining constant: ${name}=${init.raw}`);
+						found++;
+						constants[name] = init;
+						// remove declaration
+						decl.value.declarations.splice(i, 1);
+						// if it's the last, we'll remove the whole statement
+						return !decl.value.declarations.length;
+					}
+				}
+			}
+			return false;
+		})
+		.remove();
+
+	code.find(j.Identifier)
+		.filter( path => path.value.name && constants.hasOwnProperty(path.value.name) )
+		.replaceWith( path => (found++, constants[path.value.name]) );
+
+	return found ? code.toSource({ quote: 'single' }) : null;
+};