Enable strict null check for ./vs/base/test/common/history.test.ts

[gngchrs]

#65233

• "./vs/base/test/common/history.test.ts"

Not sure how to fix this. yarn strict-null-check
https://github.com/Microsoft/vscode/blob/f903e6d226f953e158deb397de871fd34dce1979/src/vs/base/test/common/history.test.ts#L116-L126

result.push(historyNavigator.current());

result is defined as a type string[]
historyNavigator.current() is defined as type <T> | null, in this case string | null.

I'm thinking of changing the types for HistoryNavigator.<method> back to just return T and not T | null

Thoughts ?

[gngchrs]

Decided to change
string[] to Array<string | null>