fix: wrong import completion when insert/replace supported

[rchl]

Fixes regression for clients that have insertReplaceSupport where completing:

import { readFil }

would result in incorrect insert:

import { readFile } from "fs"; }

The TextEdit in this case would be:

      "textEdit": {
        "insert": {
          "end": {
            "character": 16,
            "line": 0
          },
          "start": {
            "character": 0,
            "line": 0
          }
        },
        "newText": "import { readFile$1 } from \"fs\";",
        "replace": {
          "end": {
            "character": 18,
            "line": 0
          },
          "start": {
            "character": 0,
            "line": 0
          }
        }
      }

and the problem would be in the insert range.

We should not be providing both insert and replace ranges when TS completion entry has its own replacementSpan provided as in that case it's the only valid option.

@predragnikolic

[rchl]

The entry.isImportStatementCompletion check was removed as it's only provided by TS for telemetry reasons and isSnippet check covers that case already.

[predragnikolic]

this function is pretty similar to what VS Code does:

    // vscode/extensions/typescript-language-features/src/languageFeatures/completions.ts
	private getRangeFromReplacementSpan(tsEntry: Proto.CompletionEntry, completionContext: CompletionContext) {
		if (!tsEntry.replacementSpan) {
			return;
		}

		let replaceRange = typeConverters.Range.fromTextSpan(tsEntry.replacementSpan);
		// Make sure we only replace a single line at most
		if (!replaceRange.isSingleLine) {
			replaceRange = new vscode.Range(replaceRange.start.line, replaceRange.start.character, replaceRange.start.line, completionContext.line.length);
		}

		// If TS returns an explicit replacement range, we should use it for both types of completion
		return {
			inserting: replaceRange,
			replacing: replaceRange,
		};
	}

So basically if an entry has a replacementSpan, VS Code uses that replacementSpan for both insert and replace.

You took a little different approach, but it works.

[rchl]

VSCode doesn't use LSP so we can't use exactly same code but yes, it's based on VSCode's logic.

[predragnikolic]

This fixes the regression ✅