Upgrade to go1.22 and min version to go1.20 (#691)

This PR bumps the go version to 1.22 and the min version to 1.20. This
was prompted by a CI failure which I believe is related to this issue:
golang/go#55846.

Also included is a removal of a workaround for go1.19 header handling
introduced here in #406.

.github/workflows/ci.yaml

@@ -16,7 +16,7 @@ jobs:
     strategy:
       matrix:
         # when editing this list, also update steps and jobs below
-        go-version: [1.19.x, 1.20.x, 1.21.x]
+        go-version: [1.20.x, 1.21.x, 1.22.x]
     steps:
       - name: Checkout Code
         uses: actions/checkout@v4
@@ -33,14 +33,13 @@ jobs:
         # conflicting guidance, run only on the most recent supported version.
         # For the same reason, only check generated code on the most recent
         # supported version.
-        if: matrix.go-version == '1.21.x'
+        if: matrix.go-version == '1.22.x'
         run: make checkgenerate && make lint
   conformance:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        # 1.19 is omitted because conformance test runner requires 1.20+
-        go-version: [1.20.x, 1.21.x]
+        go-version: [1.20.x, 1.21.x, 1.22.x]
     steps:
       - name: Checkout Code
         uses: actions/checkout@v4
@@ -63,6 +62,6 @@ jobs:
         uses: actions/setup-go@v5
         with:
           # only the latest
-          go-version: 1.21.x
+          go-version: 1.22.x
       - name: Run Slow Tests
-        run: make slowtest
+        run: make slowtest

.github/workflows/windows.yaml

@@ -15,7 +15,7 @@ jobs:
     runs-on: windows-latest
     strategy:
       matrix:
-        go-version: [1.19.x,1.20.x,1.21.x]
+        go-version: [1.20.x, 1.21.x, 1.22.x]
     steps:
       - name: Checkout Code
         uses: actions/checkout@v4

go.mod

@@ -1,6 +1,6 @@
 module connectrpc.com/connect
 
-go 1.19
+go 1.20
 
 retract (
 	v1.10.0 // module cache poisoned, use v1.10.1
@@ -9,8 +9,8 @@ retract (
 
 require (
 	github.com/google/go-cmp v0.5.9
-	golang.org/x/net v0.17.0
+	golang.org/x/net v0.21.0
 	google.golang.org/protobuf v1.32.0
 )
 
-require golang.org/x/text v0.13.0 // indirect
+require golang.org/x/text v0.14.0 // indirect

go.sum

@@ -1,8 +1,8 @@
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-golang.org/x/net v0.17.0 h1:pVaXccu2ozPjCXewfr1S7xza/zcXTity9cCdXQYSjIM=
-golang.org/x/net v0.17.0/go.mod h1:NxSsAGuq816PNPmqtQdLE42eU2Fs7NoRIZrHJAlaCOE=
-golang.org/x/text v0.13.0 h1:ablQoSUd0tRdKxZewP80B+BaqeKJuVhuRxj/dkrun3k=
-golang.org/x/text v0.13.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
+golang.org/x/net v0.21.0 h1:AQyQV4dYCvJ7vGmJyKki9+PBdyvhkSd8EIx/qb0AYv4=
+golang.org/x/net v0.21.0/go.mod h1:bIjVDfnllIU7BJ2DNgfnXvpSvtn8VRwhlsaeUTyUS44=
+golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
+golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 google.golang.org/protobuf v1.32.0 h1:pPC6BG5ex8PDFnkbrGU3EixyhKcQ2aDuBS36lqK/C7I=
 google.golang.org/protobuf v1.32.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=

header.go

@@ -78,10 +78,3 @@ func setHeaderCanonical(h http.Header, key, value string) {
 func delHeaderCanonical(h http.Header, key string) {
 	delete(h, key)
 }
-
-// addHeaderCanonical is a shortcut for Header.Add() which
-// bypasses the CanonicalMIMEHeaderKey operation when we
-// know the key is already in canonical form.
-func addHeaderCanonical(h http.Header, key, value string) {
-	h[key] = append(h[key], value)
-}

internal/conformance/go.mod

@@ -1,6 +1,6 @@
 module connectrpc.com/connect/internal/conformance
 
-go 1.19
+go 1.20
 
 require connectrpc.com/conformance v1.0.0-rc2
 

protocol_grpc.go

@@ -539,27 +539,7 @@ func (hc *grpcHandlerConn) Close(err error) (retErr error) {
 	// as HTTP trailers. (If we had frame-level control of the HTTP/2 layer, we
 	// could send trailers-only responses as a single HEADER frame and no DATA
 	// frames, but net/http doesn't expose APIs that low-level.)
-	if !hc.wroteToBody {
-		// This block works around a bug in x/net/http2. Until Go 1.20, trailers
-		// written using http.TrailerPrefix were only sent if either (1) there's
-		// data in the body, or (2) the innermost http.ResponseWriter is flushed.
-		// To ensure that we always send a valid gRPC response, even if the user
-		// has wrapped the response writer in net/http middleware that doesn't
-		// implement http.Flusher, we must pre-declare our HTTP trailers. We can
-		// remove this when Go 1.21 ships and we drop support for Go 1.19.
-		for key := range mergedTrailers {
-			addHeaderCanonical(hc.responseWriter.Header(), headerTrailer, key)
-		}
-		hc.responseWriter.WriteHeader(http.StatusOK)
-		for key, values := range mergedTrailers {
-			for _, value := range values {
-				// These are potentially user-supplied, so we can't assume they're in
-				// canonical form. Don't use addHeaderCanonical.
-				hc.responseWriter.Header().Add(key, value)
-			}
-		}
-		return nil
-	}
+	//
 	// In net/http's ResponseWriter API, we send HTTP trailers by writing to the
 	// headers map with a special prefix. This prefixing is an implementation
 	// detail, so we should hide it and _not_ mutate the user-visible headers.
@@ -570,7 +550,7 @@ func (hc *grpcHandlerConn) Close(err error) (retErr error) {
 	for key, values := range mergedTrailers {
 		for _, value := range values {
 			// These are potentially user-supplied, so we can't assume they're in
-			// canonical form. Don't use addHeaderCanonical.
+			// canonical form.
 			hc.responseWriter.Header().Add(http.TrailerPrefix+key, value)
 		}
 	}