| 1 | package agent |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "sync" |
| 7 | "sync/atomic" |
| 8 | "testing" |
| 9 | "time" |
| 10 | |
| 11 | "reasonix/internal/config" |
| 12 | "reasonix/internal/plugin" |
| 13 | ) |
| 14 | |
| 15 | func TestMCPServerPolicyDefaultsToParallelExceptKnownStateful(t *testing.T) { |
| 16 | for name, tc := range map[string]struct { |
| 17 | entry config.PluginEntry |
| 18 | want bool |
| 19 | }{ |
| 20 | "ordinary server": {config.PluginEntry{Name: "github"}, false}, |
| 21 | "filesystem server": {config.PluginEntry{Name: "filesystem"}, false}, |
| 22 | "browser server": {config.PluginEntry{Name: "browser"}, true}, |
| 23 | "vendor-prefixed browser": {config.PluginEntry{Name: "acme-playwright-mcp"}, true}, |
| 24 | "explicit serial": {config.PluginEntry{Name: "github", Concurrency: "serial"}, true}, |
| 25 | "explicit parallel wins": {config.PluginEntry{Name: "browser", Concurrency: "parallel"}, false}, |
| 26 | } { |
| 27 | if got := mcpServerIsSerial(tc.entry); got != tc.want { |
| 28 | t.Errorf("%s: serial = %v, want %v", name, got, tc.want) |
| 29 | } |
| 30 | } |
| 31 | } |
| 32 | |
| 33 | func TestMCPRuntimeConfigurationPreservesConcurrencyPolicy(t *testing.T) { |
| 34 | runtime := &MCPCapabilityRuntime{ |
| 35 | servers: map[string]mcpRuntimeServer{}, |
| 36 | state: &mcpProxySharedState{connected: map[string]bool{}}, |
| 37 | } |
| 38 | runtime.ConfigureServers( |
| 39 | []config.PluginEntry{{Name: "github", Concurrency: " SERIAL "}}, |
| 40 | []plugin.Spec{{Name: "github"}}, |
| 41 | map[string]bool{"github": true}, |
| 42 | ) |
| 43 | if !runtime.serverIsSerial("github") { |
| 44 | t.Fatal("ConfigureServers dropped the explicit serial policy") |
| 45 | } |
| 46 | configured := runtime.configuredServers() |
| 47 | if len(configured) != 1 || configured[0].entry.Concurrency != MCPConcurrencySerial { |
| 48 | t.Fatalf("configured concurrency = %+v, want serial", configured) |
| 49 | } |
| 50 | |
| 51 | runtime.UpsertServer( |
| 52 | config.PluginEntry{Name: "browser", Concurrency: " PARALLEL "}, |
| 53 | plugin.Spec{Name: "browser"}, |
| 54 | true, |
| 55 | ) |
| 56 | if runtime.serverIsSerial("browser") { |
| 57 | t.Fatal("UpsertServer dropped the explicit parallel override") |
| 58 | } |
| 59 | configured = runtime.configuredServers() |
| 60 | foundBrowser := false |
| 61 | for _, server := range configured { |
| 62 | if server.entry.Name != "browser" { |
| 63 | continue |
| 64 | } |
| 65 | foundBrowser = true |
| 66 | if server.entry.Concurrency != MCPConcurrencyParallel { |
| 67 | t.Fatalf("upserted concurrency = %q, want parallel", server.entry.Concurrency) |
| 68 | } |
| 69 | } |
| 70 | if !foundBrowser { |
| 71 | t.Fatal("UpsertServer did not publish the browser entry") |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | func runtimeWithServers(entries ...config.PluginEntry) *MCPCapabilityRuntime { |
| 76 | r := &MCPCapabilityRuntime{servers: map[string]mcpRuntimeServer{}} |
| 77 | for _, e := range entries { |
| 78 | r.servers[e.Name] = mcpRuntimeServer{entry: e, enabled: true} |
| 79 | } |
| 80 | return r |
| 81 | } |
| 82 | |
| 83 | // Two children sharing one stdio process must not interleave on a server that |
| 84 | // carries session state, even though nothing it does looks like a write. |
| 85 | func TestMCPSerialServerNeverRunsTwoCallsAtOnce(t *testing.T) { |
| 86 | r := runtimeWithServers(config.PluginEntry{Name: "browser"}) |
| 87 | var inFlight, peak atomic.Int32 |
| 88 | var wg sync.WaitGroup |
| 89 | for range 8 { |
| 90 | wg.Go(func() { |
| 91 | err := r.withServerGate(context.Background(), "browser", func() error { |
| 92 | current := inFlight.Add(1) |
| 93 | for { |
| 94 | seen := peak.Load() |
| 95 | if current <= seen || peak.CompareAndSwap(seen, current) { |
| 96 | break |
| 97 | } |
| 98 | } |
| 99 | time.Sleep(time.Millisecond) |
| 100 | inFlight.Add(-1) |
| 101 | return nil |
| 102 | }) |
| 103 | if err != nil { |
| 104 | t.Errorf("withServerGate: %v", err) |
| 105 | } |
| 106 | }) |
| 107 | } |
| 108 | wg.Wait() |
| 109 | if got := peak.Load(); got != 1 { |
| 110 | t.Fatalf("peak concurrent calls = %d, want 1: a stateful server must be serialised", got) |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | // The shared-Host performance tradeoff must survive: ordinary servers keep |
| 115 | // running concurrently, and an unconfigured one is never gated by accident. |
| 116 | func TestMCPParallelServersStayConcurrent(t *testing.T) { |
| 117 | for _, server := range []string{"github", "unconfigured"} { |
| 118 | r := runtimeWithServers(config.PluginEntry{Name: "github"}) |
| 119 | held := make(chan struct{}) |
| 120 | released := make(chan struct{}) |
| 121 | go func() { |
| 122 | _ = r.withServerGate(context.Background(), server, func() error { |
| 123 | close(held) |
| 124 | <-released |
| 125 | return nil |
| 126 | }) |
| 127 | }() |
| 128 | <-held |
| 129 | |
| 130 | done := make(chan struct{}) |
| 131 | go func() { |
| 132 | _ = r.withServerGate(context.Background(), server, func() error { return nil }) |
| 133 | close(done) |
| 134 | }() |
| 135 | select { |
| 136 | case <-done: |
| 137 | case <-time.After(2 * time.Second): |
| 138 | t.Errorf("%s: a parallel server must not gate a second concurrent call", server) |
| 139 | } |
| 140 | close(released) |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | // A queued call abandons the gate when its own run is cancelled rather than |
| 145 | // pinning the whole session behind a stuck server. |
| 146 | func TestMCPSerialGateHonoursCancellation(t *testing.T) { |
| 147 | r := runtimeWithServers(config.PluginEntry{Name: "browser"}) |
| 148 | held := make(chan struct{}) |
| 149 | released := make(chan struct{}) |
| 150 | go func() { |
| 151 | _ = r.withServerGate(context.Background(), "browser", func() error { |
| 152 | close(held) |
| 153 | <-released |
| 154 | return nil |
| 155 | }) |
| 156 | }() |
| 157 | <-held |
| 158 | defer close(released) |
| 159 | |
| 160 | ctx, cancel := context.WithCancel(context.Background()) |
| 161 | cancel() |
| 162 | ran := false |
| 163 | err := r.withServerGate(ctx, "browser", func() error { ran = true; return nil }) |
| 164 | if err == nil || !errors.Is(err, context.Canceled) { |
| 165 | t.Fatalf("err = %v, want the cancellation surfaced", err) |
| 166 | } |
| 167 | if ran { |
| 168 | t.Fatal("a cancelled call must not execute after failing to take the gate") |
| 169 | } |
| 170 | } |
| 171 |