processDiagnosticMessages: Simplify check for uniqueness of names

[ghost]

Tested with:

diff TypeScript/src/compiler/diagnosticInformationMap.generated.ts TypeScript_1/TypeScript/src/compiler/diagnosticInformationMap.generated.ts
diff TypeScript/src/compiler/diagnosticMessages.generated.json TypeScript_1/TypeScript/src/compiler/diagnosticMessages.generated.json

No change.

[ghost]

@weswigham Any idea why gulp generate-diagnostics doesn't seem to run processDiagnosticMessages.ts? I put if (1 + 1 === 2) throw new Error("!"); at the top and it still succeeded.

[weswigham]

@Andy-MS if (needsUpdate(diagnosticMessagesJson, [generatedDiagnosticMessagesJSON, diagnosticInfoMapTs])) is checking if the generatedJSON and info map TS file are older than the input json file. Editing the actual generation script won't update the input json, so it won't be run. Add the generating ts or js file to the list of files to compare to to get it to consider it for change-time-tracking.

[ghost]

OK, I had been confused before because in the old implementation, isCaseSensitive was hard-coded to false. But we actually had the condition on backwards:

if (caseSensitive) {
    s1 = s1.toLowerCase();
    s2 = s2.toLowerCase();
}

Since isCaseSensitive was always false, stringEquals was just a == test.

[weswigham]

This removes the automatic generation of noncolliding names and introduces case sensitivity. I think the case sensitivity is probably bad - we probably shouldn't be introducing multiple diagnostics which only differ in case (even if that was the old behavior), and it's good to catch that here. The automatic collision renaming... well, if we're not triggering it then I guess it doesn't really have a point and is fine to remove.

[ghost]

@weswigham We already have both Diagnostics.file and Diagnostics.FILE. In one case we want this word to appear in lowercase, in another we want it uppercase. I don't see any problem with that?
This PR does not introduce case sensitivity, it just makes it obvious that that was always the way things were done.

[weswigham]

Alright.