NotificationsYou must be signed in to change notification settings
Fork1.9k
Star15k

Remove const enum and add ErrorValue in index.d.ts#1317

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to ourterms of service andprivacy statement. We’ll occasionally send you account related emails.

Already on GitHub?Sign in to your account

Jump to bottom

Merged

Siemienik merged 1 commit intoexceljs:masterfromaplum:remove-ts-const-enum

Jun 8, 2020

Merged

Remove const enum and add ErrorValue in index.d.ts#1317

Siemienik merged 1 commit intoexceljs:masterfromaplum:remove-ts-const-enum

Jun 8, 2020

Conversation

Copy link

Contributor

aplum commentedJun 5, 2020

Summary

Usingconst enum in .d.ts files breaks compilation with--isolatedModules. Instead, normalenums have been used where a corresponding object exists at runtime.PaperSize does not exist at runtime, and so has been left asconst enum for backwards compatibility.

This also adds a declaration forErrorValue since it exists at runtime but had no TS definition. This does result in some duplication withCellErrorValue, but changingCellErrorValue to useErrorValue would be a breaking change.

A comparable fix and explanation for the problem with usingconst enum can be found atchalk/chalk#296, and some further explanation athttps://ncjamieson.com/dont-export-const-enums/ andthis comment.

Test plan

I created a small project to test this while making changes. Example file:

import{ValueType,CellModel}from'exceljs';letvt:ValueType=ValueType.Date;constvtString=ValueType.String;exportconstcm1:Partial<CellModel>={type:vt};exportconstcm2:Partial<CellModel>={type:vtString};exportconstcm3:Partial<CellModel>={type:ValueType.Boolean};

Before this PR:

No errors withisolatedModules: false
Errors withisolatedModules: true

With this PR:

No errors withisolatedModules: false
No errors withisolatedModules: true

Remove const enum and add ErrorValue in index.d.ts

622eb22

Using `const enum` in .d.ts files breaks compilation with `--isolatedModules`. Instead, normal `enum`s have been used where a corresponding object exists at runtime. `PaperSize` does not exist at runtime, and so has been left as `const enum` for backwards compatibility.This also adds a declaration for `ErrorValue` since it exists at runtime but had no TS definition. This does result in some duplication with `CellErrorValue`, but changing `CellErrorValue` to use `ErrorValue` would be a breaking change.