Counter-intuitive "editor.suggestSelection" behavior when completion is "kept open"

- VSCode Version: 1.25 - OS Version: Windows 10 In the Haxe extension, we want to support the following two use cases: - `identifier.|` - request completion for the fields within `identifier`. - `some.package.|` - filter packages / types by the dot path that's currently being typed. In this case, the completion items don't change when typing a dot, so the suggest widget should simple be kept open (but filtered accordingly). To support of the first use case, we need to register `"."` as a trigger character, which means that `provideCompletionItems()` is invoked for the other case as well, even though it wouldn't be necessary there. But so far so good, we can simply return the same completion items again to keep the suggest widget open, and adjust the `range` of the items to match against the entire dot path typed so far. Here's a simple extension that simulates that: ```ts 'use strict'; import * as vscode from 'vscode'; export function activate(context: vscode.ExtensionContext) { vscode.languages.registerCompletionItemProvider('plaintext', { provideCompletionItems(doc, pos, token, context) { var range = new vscode.Range(new vscode.Position(0, 0), pos); if (doc.getText(range) == "Json.") { return [ {label: "parse"}, {label: "stringify"} ]; } return [ {label: "haxe", range: range}, {label: "haxe.ds", range: range}, {label: "haxe.ds.Map", range: range}, {label: "haxe.ds.BalancedTree", range: range}, {label: "Json - haxe.Json", insertText: "Json", range: range} ]; } }, "."); } ``` This approach actually works quite well, but it causes an annoying interaction with the default behavior of `"editor.suggestSelection"` (default is `recentlyUsed`). If the `Json - haxe.Json` entry has been selected before, it is auto-selected when typing the dot…