When I have a structure like this:

• a.ts
• b.ts And b.ts import a.ts.

And I have set both a.ts and b.ts as inputs to be used as exports. Then, when using rollup dts, it will generate two separate compilation tasks for a and b respectively. When I compile b first and then a, i.e., when the inputs are written as [b.ts, a.ts] (let's not worry about the order for now, as I have simplified the problem).

npm run build:rollup

It will throw an error:

The reason is that when compiling a.ts, the program is reused. However, since b.ts has already been compiled, the dependency of a.ts in b.ts is also recorded in the source files of the program corresponding to the entry point of b.ts. When rollup dts detects that a.ts exists in the source files of the above b_program, it directly uses b_program instead of the program corresponding to a.ts.

const existingProgram = programs.find((p) => !!p.getSourceFile(fileName));

For this case, I have created a simulation that can run this command:

npm run build:a_by_b

Line 46 will never be output, which is the reason for the error reported by rollup-plugin-dts.

Therefore, here we need to check if the target file of toModule is an entry point. In this case, we need to find the corresponding program. I have a patch that fixes it.

npm run build:rollup_with_patch