TypeError at ast.js:6:43

[donmanguno]

I'm trying to build a project locally, a project I didn't write, and this is my first time using svelte, or rollup, or esifycss. I'm using esifycss via rollup-plugin-embed-css, on which step the build fails with the stacktrace below.

TypeError: Cannot read properties of null (reading 'type')
    at isObjectExpression (/.../node_modules/esifycss/lib/minifier/ast.js:6:43)
    at extractCSSFromArrayExpression (/.../node_modules/esifycss/lib/minifier/extractCSSFromArrayExpression.js:9:46)
    at ExpressionStatement (/.../node_modules/esifycss/lib/minifier/parseCSSModuleScript.js:24:102)
    at c (/.../node_modules/acorn-walk/dist/walk.js:30:20)
    at Object.skipThrough (/.../node_modules/acorn-walk/dist/walk.js:186:39)

I'm able to resolve it by simply editing /minifier/ast.js to use optional chaining:

const isObjectExpression = (node) => node?.type === 'ObjectExpression';

Would changing this behavior break something? Seems to me that if node is undefined or null isObjectExpression should be as well (as well as isProgramNode and isArrayExpression).