Adress comments on non-destructive upgrades.

extensions/ql-vscode/src/cli.ts

@@ -651,6 +651,7 @@ export class CodeQLCliServer implements Disposable {
    * Gets information necessary for upgrading a database.
    * @param dbScheme the path to the dbscheme of the database to be upgraded.
    * @param searchPath A list of directories to search for upgrade scripts.
+   * @param targetDbScheme The dbscheme to try to upgrade to.
    * @returns A list of database upgrade script directories
    */
   resolveUpgrades(dbScheme: string, searchPath: string[], targetDbScheme?: string): Promise<UpgradesInfo> {

extensions/ql-vscode/src/pure/messages.ts

@@ -418,7 +418,7 @@ export interface CompileUpgradeParams {
  */
 export interface CompileUpgradeSequenceParams {
   /**
-   * The sequence of upogrades to compile
+   * The sequence of upgrades to compile
    */
   upgradePaths: string[];
   /**

extensions/ql-vscode/src/upgrades.ts

@@ -23,11 +23,9 @@ const MAX_UPGRADE_MESSAGE_LINES = 10;
  * 
  * This requires 3 features. The ability to compile an upgrade sequence; The ability to 
  * run a non-destructive upgrades as a query; the ability to specify a target when 
- * resolving upgrades.
+ * resolving upgrades. We check for a version of codeql that has all three features.
  */
 export async function hasNondestructiveUpgradeCapabilities(qs: qsClient.QueryServerClient): Promise<boolean> {
-  // TODO change to actual version when known
-  // Note it is probably something 2.4.something
   return semver.gte(await qs.cliServer.getVersion(), '2.4.1');
 }
 
@@ -46,6 +44,9 @@ export async function compileDatabaseUpgradeSequence(qs: qsClient.QueryServerCli
   if (db.contents === undefined || db.contents.dbSchemeUri === undefined) {
     throw new Error('Database is invalid, and cannot be upgraded.');
   }
+  if (!hasNondestructiveUpgradeCapabilities(qs)) {
+    throw new Error('The version of codeql is to old to run non-destructive upgrades.');
+  }
   // If possible just compile the upgrade sequence
   return await qs.sendRequest(messages.compileUpgradeSequence, {
     upgradeTempDir: currentUpgradeTmp.name,
@@ -72,7 +73,7 @@ async function compileDatabaseUpgrade(
     }
     // We have the upgrades we want but compileUpgrade
     // requires searching for them.  So we use the parent directories of the upgrades
-    // as the uograde path.
+    // as the upgrade path.
     const parentDirs = resolvedSequence.map(dir => path.dirname(dir));
     const uniqueParentDirs = new Set(parentDirs);
     progress({