interface IX123abc throw an error

[thomas3577]

Bug Report

• TSLint V5.15.0:
• TypeScript V3.2.4:
• Running TSLint via: CLI, VSCode

TypeScript code being linted

interface II18nService {
}

class I18nService implements II18nService {
}

with tslint.json configuration:

...
"interface-name": [
  true,
  "always-prefix"
],
...

Actual behavior

ERROR: .../i18n.service.ts: - interface name must start with a capitalized I

Expected behavior

No Error

Examples that work:

• IAnything
• IIanything
• INanything

Examples that don't work:

• II18anything
• IN18anything

It seems the numbers in the interface-name are a problem.

And by the way: A Class with the name I18nService works fine.

[VincentLanglet]

I did this #4626

The main issue was the function isLowerCase and isUpperCase

isLowerCase('3') = true
isUpperCase('3') = true

[chulanovskyi]

The problem still exists. After upgrading from 5.14 to 5.15 started to receive such errors:

I suppose that tslint expects that the name of the interface should start from two (?) capital letters? Is this documented somewhere?

[VincentLanglet]

@chulanovskyi The PR is not already merge.

But you don't have the same issue. The doc can be updated this way

Requires interface names to begin with a capital ‘I’ prefix

tslint expect IInjectedToggleStateProps in your case