1 files changed, 69 insertions, 0 deletions
diff --git a/internal/lsp/context_test.go b/internal/lsp/context_test.go
new file mode 100644
index 0000000..32834b8
--- /dev/null
+++ b/internal/lsp/context_test.go
@@ -0,0 +1,69 @@
+package lsp
+
+import (
+    "strconv"
+    "strings"
+    "testing"
+)
+
+func TestWindowContext_Bounds(t *testing.T) {
+    s := newTestServer()
+    s.windowLines = 4 // half=2
+    s.maxContextTokens = 9999
+    lines := make([]string, 10)
+    for i := 0; i < 10; i++ {
+        lines[i] = "L" + strconv.Itoa(i)
+    }
+    text := strings.Join(lines, "\n")
+    uri := "file:///w.go"
+    s.setDocument(uri, text)
+    got := s.windowContext(uri, Position{Line: 5, Character: 0})
+    // expect lines 3..7 inclusive
+    want := strings.Join(lines[3:8], "\n")
+    if got != want {
+        t.Fatalf("window context got %q want %q", got, want)
+    }
+}
+
+func TestBuildAdditionalContext_Minimal(t *testing.T) {
+    s := newTestServer()
+    s.contextMode = "minimal"
+    if ctx, ok := s.buildAdditionalContext(false, "file:///x.go", Position{}); ok || ctx != "" {
+        t.Fatalf("expected no context in minimal mode; got ok=%v ctx=%q", ok, ctx)
+    }
+}
+
+func TestBuildAdditionalContext_FileOnNewFunc(t *testing.T) {
+    s := newTestServer()
+    s.contextMode = "file-on-new-func"
+    s.maxContextTokens = 9999
+    uri := "file:///x.go"
+    body := "package x\n\nfunc a(){}\n" 
+    s.setDocument(uri, body)
+    if ctx, ok := s.buildAdditionalContext(true, uri, Position{}); !ok || ctx == "" {
+        t.Fatalf("expected full context when new func; ok=%v ctx=%q", ok, ctx)
+    }
+    if ctx, ok := s.buildAdditionalContext(false, uri, Position{}); ok || ctx != "" {
+        t.Fatalf("expected no context when not new func; ok=%v ctx=%q", ok, ctx)
+    }
+}
+
+func TestBuildAdditionalContext_AlwaysFull(t *testing.T) {
+    s := newTestServer()
+    s.contextMode = "always-full"
+    s.maxContextTokens = 9999
+    uri := "file:///x.go"
+    body := "line1\nline2\n"
+    s.setDocument(uri, body)
+    if ctx, ok := s.buildAdditionalContext(false, uri, Position{}); !ok || ctx == "" {
+        t.Fatalf("expected context in always-full; ok=%v ctx=%q", ok, ctx)
+    }
+}
+
+func TestTruncateToApproxTokens(t *testing.T) {
+    text := strings.Repeat("abcd", 10) // 40 chars
+    got := truncateToApproxTokens(text, 5) // ~20 chars
+    if len(got) > 5*4 {
+        t.Fatalf("truncate exceeded budget: got len=%d budget=%d", len(got), 5*4)
+    }
+}