fix(tools): symbol_workspace TotalCount is capped at about twice maxResults #115

Problem

symbol_workspace returns a TotalCount that looks like the number of matching symbols, but it stops counting at about twice maxResults.

In VisualStudioService.SearchWorkspaceSymbolsAsync:

• The search stops once maxResults * 2 matching symbols have been collected (the maxResults * 2 limit passed to CollectProjectSymbols, and the break after it). Symbols after that are never looked at.
• TotalCount is set to allSymbols.Count, so it can't go much above 2 * maxResults.
• The limit is only checked when the search starts a project item or a list of code elements, not after each symbol is added. So the search runs a variable amount past the limit, and TotalCount isn't even a fixed cap.

So with 1,000 symbols matching the query and the default maxResults = 100, TotalCount comes back as about 200 instead of 1,000.

Truncated is correct. Only matching symbols are collected, so allSymbols.Count > maxResults is true exactly when more symbols matched than were returned.

Repro

1. Open a solution with many symbols matching a short query (for example Get).
2. Call symbol_workspace with query: "Get" and maxResults: 5.
3. TotalCount is about 10, however many symbols actually match.

Expected

TotalCount should not look like a total when it isn't. Two ways to fix it:

• Count every match. Search the whole solution, but only build SymbolInfo for the first maxResults. This is accurate, but it can be slow: reading FileCodeModel for every file is expensive, and the maxResults description ("Use lower values for faster results on large solutions") suggests the early stop is deliberate.
• Keep the early stop and say so. Document TotalCount as a lower bound, or rename or drop it, so callers don't read it as the real total.

Also

• maxResults: 0 or below makes the limit 0 or negative, so nothing is collected. The tool then says "No symbols matching '...' found in the solution." even when there are matches. These values should be rejected or handled.
• SearchWorkspaceSymbolsAsync runs the name filter (.Where(...)) a second time on allSymbols. CollectCodeElements already only adds matching symbols, so the second filter changes nothing.

Related

#113 (fixed in #114) was the same kind of problem in errors_list.