How to deal with the problem of TS2367 error after the replacement code? - rollup

Question

I use rollup-replace as the variable switch of the builder in the project, but I have encountered a problem when using it with TypeScript, and I always give me errors like this:
semantic error TS2367: This condition will always return'true' since the types'boolean' and'string' have no overlap.
I will write code like this in my code
// a.ts
import Prod from './prod';
import Pre from './pre';
If(process.env.PROD === ’true’){
console.log(‘is prod’);
Prod.init();
} else {
console.log(‘is pre’);
Pre.init();
}
// rollup.config.js
import typescript from 'rollup-plugin-typescript2';
import resolve from '#rollup/plugin-node-resolve';
import commonjs from '#rollup/plugin-commonjs';
import replace from '#rollup/plugin-replace';
export default [
{
input: 'src/a.ts',
output: { file: 'dist/a.js', format: 'iife' },
plugins: [
replace({ values: { 'process.env.PROD': JSON.stringify(true) }, preventAssignment: true }),
resolve({ browser: true }),
commonjs(),
typescript(),
]
}
]
In the above build code, replace needs to precede resolve, because it is necessary to use replace to avoid useless JS from being imported into the bundle file.
Who can help me solve this meaningless error message?

Answer 1

In the rollup document, I found the advanced usage of treeshake.moduleSideEffects, which talked about the ability I want to achieve.
import typescript from 'rollup-plugin-typescript2';
import resolve from '#rollup/plugin-node-resolve';
import commonjs from '#rollup/plugin-commonjs';
import replace from '#rollup/plugin-replace';
export default [
{
input: 'src/a.ts',
output: { file: 'dist/a.js', format: 'iife' },
plugins: [
replace({ values: { 'process.env.PROD': JSON.stringify(true) }, preventAssignment: true }),
resolve({ browser: true }),
commonjs(),
typescript(),
],
treeshake: {
moduleSideEffects: false, // Prune unused pure external imports
},
}
]