From ef188388102b0377ed506b8767536233575965bb Mon Sep 17 00:00:00 2001
From: Paul Buetow <paul@buetow.org>
Date: Tue, 19 Aug 2025 21:41:33 +0300
Subject: lsp: reduce eager completions and add throttling\n\n- Defaults:
 remove ';' and '?' from trigger characters\n- Add min-typed-prefix heuristic
 for LLM completions (>=2 chars)\n- Add simple time-based throttle between LLM
 completions (default 900ms)\n- Tests: verify default triggers and skip logic
 (throttle + min prefix)\n- Config example: update trigger_characters list

---
 internal/lsp/completion_throttle_test.go | 75 ++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100644 internal/lsp/completion_throttle_test.go

(limited to 'internal/lsp/completion_throttle_test.go')

diff --git a/internal/lsp/completion_throttle_test.go b/internal/lsp/completion_throttle_test.go
new file mode 100644
index 0000000..2de8edb
--- /dev/null
+++ b/internal/lsp/completion_throttle_test.go
@@ -0,0 +1,75 @@
+package lsp
+
+import (
+    "bytes"
+    "context"
+    "log"
+    "testing"
+    "time"
+
+    "hexai/internal/llm"
+)
+
+// countingLLM counts Chat calls; minimal implementation for tests.
+type countingLLM struct{ calls int }
+
+func (f *countingLLM) Chat(_ context.Context, _ []llm.Message, _ ...llm.RequestOption) (string, error) {
+    f.calls++
+    return "x := 1", nil
+}
+func (f *countingLLM) Name() string         { return "fake" }
+func (f *countingLLM) DefaultModel() string { return "m" }
+
+func TestDefaultTriggerChars_DoesNotIncludeSemicolonOrQuestion(t *testing.T) {
+    var buf bytes.Buffer
+    logger := log.New(&buf, "", 0)
+    s := NewServer(bytes.NewBuffer(nil), &buf, logger, ServerOptions{})
+    has := func(ch string) bool {
+        for _, c := range s.triggerChars {
+            if c == ch { return true }
+        }
+        return false
+    }
+    if has(";") || has("?") {
+        t.Fatalf("default trigger chars should not include ';' or '?' got=%v", s.triggerChars)
+    }
+}
+
+func TestTryLLMCompletion_ThrottleSkipsRapidCalls(t *testing.T) {
+    // Build server with long min interval and set last completion to now
+    s := &Server{ maxTokens: 32 }
+    s.minCompletionInterval = time.Hour
+    s.lastLLMCompletion = time.Now()
+    fake := &countingLLM{}
+    s.llmClient = fake
+    // Position with adequate prefix to avoid prefix heuristic from skipping
+    p := CompletionParams{ Position: Position{ Line: 0, Character: 3 }, TextDocument: TextDocumentIdentifier{URI: "file://x.go"} }
+    items, ok := s.tryLLMCompletion(p, "", "foo", "", "", "", false, "")
+    if !ok {
+        t.Fatalf("expected ok=true even when throttled")
+    }
+    if len(items) != 0 {
+        t.Fatalf("expected zero items when throttled, got %d", len(items))
+    }
+    if fake.calls != 0 {
+        t.Fatalf("LLM Chat should not be called when throttled; calls=%d", fake.calls)
+    }
+}
+
+func TestTryLLMCompletion_MinPrefixSkipsEarly(t *testing.T) {
+    s := &Server{ maxTokens: 32 }
+    fake := &countingLLM{}
+    s.llmClient = fake
+    // Only 1 identifier character before cursor
+    p := CompletionParams{ Position: Position{ Line: 0, Character: 1 }, TextDocument: TextDocumentIdentifier{URI: "file://x.go"} }
+    items, ok := s.tryLLMCompletion(p, "", "a", "", "", "", false, "")
+    if !ok {
+        t.Fatalf("expected ok=true when skipped by min-prefix heuristic")
+    }
+    if len(items) != 0 {
+        t.Fatalf("expected zero items when min-prefix not satisfied")
+    }
+    if fake.calls != 0 {
+        t.Fatalf("LLM Chat should not be called when min-prefix not met; calls=%d", fake.calls)
+    }
+}
-- 
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