src/vs/workbench/services/editor/browser/editorResolverService.ts/EditorResolverService/convertOldAssociationFormat
class EditorResolverService:	private convertOldAssociationFormat(): void {
		const rawAssociations = this.configurationService.getValue<EditorAssociations | { [fileNamePattern: string]: string }>(editorsAssociationsSettingId) || [];
		// If it's not an array, then it's the new format
		if (!Array.isArray(rawAssociations)) {
			return;
		}
		const newSettingObject = Object.create(null);
		// Make the correctly formatted object from the array and then set that object
		for (const association of rawAssociations) {
			if (association.filenamePattern) {
				newSettingObject[association.filenamePattern] = association.viewType;
			}
		}
		this.logService.info(`Migrating ${editorsAssociationsSettingId}`);
		this.configurationService.updateValue(editorsAssociationsSettingId, newSettingObject);
	}