Boolean CLI options in standard "--someFlag=someValue" form fail with "error TS5023: Unknown compiler option..."

[broofa]

Bug Report

tl;dr: User's expect to assign CLI flag options with an equal sign. E.g.--flag=value. That this fails in tsc with an unobvious error is confusing. It misleads users into thinking there isn't a way of disabling options from the command line. For example:

Even if you wanted to forgo the speed benefits of "incremental"... you can't turn it off temporarily because there is no --noIncremental (or analogous) flag.

The form above is wide-spread, especially within the JS community ...

• node's command line options
• commander.js options
• yargs options
• minimist options

🔎 Search Terms

error TS5023: Unknown compiler option

🕗 Version & Regression Information

Boolean CLI options were first introduced in #11798 , but have never supported the standard --flag=value format

• This is a crash
• This changed between versions ______ and _______
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about _________
• I was unable to test this on prior versions because _______

🙁 Actual behavior

Providing boolean CLI options like --incremental=false, --noEmit=false, and so on all result in a TS5023: Unknown compiler option error.

🙂 Expected behavior

Using the standard double-dash notation of "--flagName=flagValue" (.e.g --incremental=false) should work as expected.