From b636b1633b2c167ff4e2209ae1953a1c0843c303 Mon Sep 17 00:00:00 2001 From: Robert Findley Date: Thu, 18 Sep 2025 08:30:53 -0400 Subject: [PATCH] mcp: fix flaky ExampleLoggingTransport (#483) Reads are technically racy with writes. Sort for stability. --- docs/troubleshooting.md | 13 ++++++++----- mcp/transport_example_test.go | 18 +++++++++++++----- 2 files changed, 21 insertions(+), 10 deletions(-) diff --git a/docs/troubleshooting.md b/docs/troubleshooting.md index c0f021b..0f990ed 100644 --- a/docs/troubleshooting.md +++ b/docs/troubleshooting.md @@ -39,12 +39,15 @@ func ExampleLoggingTransport() { if _, err := client.Connect(ctx, logTransport, nil); err != nil { log.Fatal(err) } - fmt.Println(b.String()) - // Output: - // write: {"jsonrpc":"2.0","id":1,"method":"initialize","params":{"capabilities":{"roots":{"listChanged":true}},"clientInfo":{"name":"client","version":"v0.0.1"},"protocolVersion":"2025-06-18"}} - // read: {"jsonrpc":"2.0","id":1,"result":{"capabilities":{"logging":{}},"protocolVersion":"2025-06-18","serverInfo":{"name":"server","version":"v0.0.1"}}} - // write: {"jsonrpc":"2.0","method":"notifications/initialized","params":{}} + // Sort for stability: reads are concurrent to writes. + for _, line := range slices.Sorted(strings.SplitSeq(b.String(), "\n")) { + fmt.Println(line) + } + // Output: + // read: {"jsonrpc":"2.0","id":1,"result":{"capabilities":{"logging":{}},"protocolVersion":"2025-06-18","serverInfo":{"name":"server","version":"v0.0.1"}}} + // write: {"jsonrpc":"2.0","id":1,"method":"initialize","params":{"capabilities":{"roots":{"listChanged":true}},"clientInfo":{"name":"client","version":"v0.0.1"},"protocolVersion":"2025-06-18"}} + // write: {"jsonrpc":"2.0","method":"notifications/initialized","params":{}} } ``` diff --git a/mcp/transport_example_test.go b/mcp/transport_example_test.go index dcf1a8b..064ab0f 100644 --- a/mcp/transport_example_test.go +++ b/mcp/transport_example_test.go @@ -2,6 +2,9 @@ // Use of this source code is governed by an MIT-style // license that can be found in the LICENSE file. +// Uses strings.SplitSeq. +//go:build go1.24 + package mcp_test import ( @@ -9,6 +12,8 @@ import ( "context" "fmt" "log" + "slices" + "strings" "github.com/modelcontextprotocol/go-sdk/mcp" ) @@ -29,12 +34,15 @@ func ExampleLoggingTransport() { if _, err := client.Connect(ctx, logTransport, nil); err != nil { log.Fatal(err) } - fmt.Println(b.String()) - // Output: - // write: {"jsonrpc":"2.0","id":1,"method":"initialize","params":{"capabilities":{"roots":{"listChanged":true}},"clientInfo":{"name":"client","version":"v0.0.1"},"protocolVersion":"2025-06-18"}} - // read: {"jsonrpc":"2.0","id":1,"result":{"capabilities":{"logging":{}},"protocolVersion":"2025-06-18","serverInfo":{"name":"server","version":"v0.0.1"}}} - // write: {"jsonrpc":"2.0","method":"notifications/initialized","params":{}} + // Sort for stability: reads are concurrent to writes. + for _, line := range slices.Sorted(strings.SplitSeq(b.String(), "\n")) { + fmt.Println(line) + } + // Output: + // read: {"jsonrpc":"2.0","id":1,"result":{"capabilities":{"logging":{}},"protocolVersion":"2025-06-18","serverInfo":{"name":"server","version":"v0.0.1"}}} + // write: {"jsonrpc":"2.0","id":1,"method":"initialize","params":{"capabilities":{"roots":{"listChanged":true}},"clientInfo":{"name":"client","version":"v0.0.1"},"protocolVersion":"2025-06-18"}} + // write: {"jsonrpc":"2.0","method":"notifications/initialized","params":{}} } // !-loggingtransport