| 1 | package jmxbridge |
| 2 | |
| 3 | import ( |
| 4 | "bufio" |
| 5 | "context" |
| 6 | "encoding/json" |
| 7 | "io" |
| 8 | "os" |
| 9 | "sync" |
| 10 | "testing" |
| 11 | "time" |
| 12 | ) |
| 13 | |
| 14 | type testLogger struct{} |
| 15 | |
| 16 | func (testLogger) Debugf(string, ...any) {} |
| 17 | func (testLogger) Infof(string, ...any) {} |
| 18 | func (testLogger) Warningf(string, ...any) {} |
| 19 | func (testLogger) Errorf(string, ...any) {} |
| 20 | |
| 21 | type fakeProcess struct { |
| 22 | stdinR *io.PipeReader |
| 23 | stdinW *io.PipeWriter |
| 24 | stdoutR *io.PipeReader |
| 25 | stdoutW *io.PipeWriter |
| 26 | stderrR *io.PipeReader |
| 27 | stderrW *io.PipeWriter |
| 28 | done chan struct{} |
| 29 | handler func(map[string]any) Response |
| 30 | } |
| 31 | |
| 32 | func newFakeProcess(handler func(map[string]any) Response) *fakeProcess { |
| 33 | stdinR, stdinW := io.Pipe() |
| 34 | stdoutR, stdoutW := io.Pipe() |
| 35 | stderrR, stderrW := io.Pipe() |
| 36 | return &fakeProcess{ |
| 37 | stdinR: stdinR, |
| 38 | stdinW: stdinW, |
| 39 | stdoutR: stdoutR, |
| 40 | stdoutW: stdoutW, |
| 41 | stderrR: stderrR, |
| 42 | stderrW: stderrW, |
| 43 | done: make(chan struct{}), |
| 44 | handler: handler, |
| 45 | } |
| 46 | } |
| 47 | |
| 48 | func (p *fakeProcess) Start() error { |
| 49 | go p.run() |
| 50 | return nil |
| 51 | } |
| 52 | |
| 53 | func (p *fakeProcess) run() { |
| 54 | defer close(p.done) |
| 55 | defer p.stdoutW.Close() |
| 56 | defer p.stderrW.Close() |
| 57 | scanner := bufio.NewScanner(p.stdinR) |
| 58 | for scanner.Scan() { |
| 59 | line := scanner.Text() |
| 60 | var cmd map[string]any |
| 61 | if err := json.Unmarshal([]byte(line), &cmd); err != nil { |
| 62 | continue |
| 63 | } |
| 64 | resp := p.handler(cmd) |
| 65 | payload, _ := json.Marshal(resp) |
| 66 | _, _ = p.stdoutW.Write(append(payload, '\n')) |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | func (p *fakeProcess) Stdin() io.WriteCloser { return p.stdinW } |
| 71 | func (p *fakeProcess) Stdout() io.ReadCloser { return p.stdoutR } |
| 72 | func (p *fakeProcess) Stderr() io.ReadCloser { return p.stderrR } |
| 73 | func (p *fakeProcess) Wait() error { <-p.done; return nil } |
| 74 | |
| 75 | func TestClientStartAndSend(t *testing.T) { |
| 76 | var call int |
| 77 | handler := func(cmd map[string]any) Response { |
| 78 | call++ |
| 79 | if call == 1 { |
| 80 | return Response{Status: "OK"} |
| 81 | } |
| 82 | return Response{Status: "OK", Data: map[string]any{"value": 123}} |
| 83 | } |
| 84 | |
| 85 | var procMu sync.Mutex |
| 86 | var proc *fakeProcess |
| 87 | |
| 88 | factory := func(ctx context.Context, javaPath, jarPath string) (process, error) { |
| 89 | procMu.Lock() |
| 90 | defer procMu.Unlock() |
| 91 | proc = newFakeProcess(handler) |
| 92 | return proc, nil |
| 93 | } |
| 94 | |
| 95 | client, err := NewClient(Config{JarPath: "helper.jar"}, testLogger{}, WithProcessFactory(factory)) |
| 96 | if err != nil { |
| 97 | t.Fatalf("NewClient failed: %v", err) |
| 98 | } |
| 99 | |
| 100 | if err := client.Start(context.Background(), Command{"command": "INIT"}); err != nil { |
| 101 | t.Fatalf("Start failed: %v", err) |
| 102 | } |
| 103 | |
| 104 | resp, err := client.Send(context.Background(), Command{"command": "SCRAPE"}) |
| 105 | if err != nil { |
| 106 | t.Fatalf("Send failed: %v", err) |
| 107 | } |
| 108 | |
| 109 | if value := resp.Data["value"]; value != float64(123) { |
| 110 | t.Fatalf("unexpected response data: %#v", resp.Data) |
| 111 | } |
| 112 | |
| 113 | client.Shutdown() |
| 114 | } |
| 115 | |
| 116 | func TestClientErrorStatus(t *testing.T) { |
| 117 | var call int |
| 118 | handler := func(cmd map[string]any) Response { |
| 119 | call++ |
| 120 | if call == 1 { |
| 121 | return Response{Status: "OK"} |
| 122 | } |
| 123 | return Response{Status: "ERROR", Message: "boom"} |
| 124 | } |
| 125 | |
| 126 | factory := func(ctx context.Context, javaPath, jarPath string) (process, error) { |
| 127 | return newFakeProcess(handler), nil |
| 128 | } |
| 129 | |
| 130 | client, err := NewClient(Config{JarPath: "helper.jar"}, testLogger{}, WithProcessFactory(factory)) |
| 131 | if err != nil { |
| 132 | t.Fatalf("NewClient failed: %v", err) |
| 133 | } |
| 134 | |
| 135 | if err := client.Start(context.Background(), Command{"command": "INIT"}); err != nil { |
| 136 | t.Fatalf("Start failed: %v", err) |
| 137 | } |
| 138 | |
| 139 | if _, err := client.Send(context.Background(), Command{"command": "SCRAPE"}); err == nil { |
| 140 | t.Fatalf("expected error status failure") |
| 141 | } |
| 142 | |
| 143 | client.Shutdown() |
| 144 | } |
| 145 | |
| 146 | func TestClientCancellation(t *testing.T) { |
| 147 | handler := func(cmd map[string]any) Response { |
| 148 | time.Sleep(200 * time.Millisecond) |
| 149 | return Response{Status: "OK"} |
| 150 | } |
| 151 | |
| 152 | factory := func(ctx context.Context, javaPath, jarPath string) (process, error) { |
| 153 | return newFakeProcess(handler), nil |
| 154 | } |
| 155 | |
| 156 | client, err := NewClient(Config{JarPath: "helper.jar"}, testLogger{}, WithProcessFactory(factory)) |
| 157 | if err != nil { |
| 158 | t.Fatalf("NewClient failed: %v", err) |
| 159 | } |
| 160 | |
| 161 | if err := client.Start(context.Background(), Command{"command": "INIT"}); err != nil { |
| 162 | t.Fatalf("Start failed: %v", err) |
| 163 | } |
| 164 | |
| 165 | ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond) |
| 166 | defer cancel() |
| 167 | |
| 168 | if _, err := client.Send(ctx, Command{"command": "SCRAPE"}); err == nil { |
| 169 | t.Fatalf("expected cancellation error") |
| 170 | } |
| 171 | |
| 172 | client.Shutdown() |
| 173 | } |
| 174 | |
| 175 | func TestClientWritesJar(t *testing.T) { |
| 176 | jarData := []byte("fake jar contents") |
| 177 | client, err := NewClient(Config{JarData: jarData, JarFileName: "helper.jar"}, testLogger{}, WithProcessFactory(func(ctx context.Context, javaPath, jarPath string) (process, error) { |
| 178 | if _, err := os.Stat(jarPath); err != nil { |
| 179 | t.Fatalf("jar file not written: %v", err) |
| 180 | } |
| 181 | return newFakeProcess(func(cmd map[string]any) Response { return Response{Status: "OK"} }), nil |
| 182 | })) |
| 183 | if err != nil { |
| 184 | t.Fatalf("NewClient failed: %v", err) |
| 185 | } |
| 186 | |
| 187 | if err := client.Start(context.Background(), Command{"command": "INIT"}); err != nil { |
| 188 | t.Fatalf("Start failed: %v", err) |
| 189 | } |
| 190 | |
| 191 | path := client.jarPath |
| 192 | client.Shutdown() |
| 193 | if _, err := os.Stat(path); err == nil { |
| 194 | t.Fatalf("jar file should be removed on shutdown") |
| 195 | } |
| 196 | } |