cmd/pushtx, .github/workflows: add build workflow, show raw hex in output

Co-authored-by: drQedwards <213266729+drQedwards@users.noreply.github.com>

.github/workflows/build.yml

@@ -0,0 +1,37 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - master
+      - copilot/**
+  pull_request:
+    branches:
+      - master
+  workflow_dispatch:
+
+jobs:
+  build:
+    name: Build All
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: false
+
+      - uses: actions/cache@v4
+        with:
+          path: build/cache
+          key: ${{ runner.os }}-build-tools-cache-${{ hashFiles('build/checksums.txt') }}
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.24'
+          cache: false
+
+      - name: Build all commands
+        run: make all
+
+      - name: Run pushtx tests
+        run: go test ./cmd/pushtx/ -v

cmd/pushtx/main.go

@@ -107,6 +107,10 @@ func run(args []string, stdin io.Reader) error {
 	}
 	fmt.Println("Transaction submitted successfully")
 	fmt.Println("Hash:", hash.Hex())
+
+	// Print the raw hex transaction as the last output for easy
+	// copy-paste into block explorers like etherscan.io/pushTx.
+	fmt.Println("Raw tx: 0x" + hex.EncodeToString(rawTx))
 	return nil
 }
 

cmd/pushtx/main_test.go

@@ -19,9 +19,11 @@ package main
 import (
 	"crypto/ecdsa"
 	"encoding/json"
+	"io"
 	"math/big"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"strings"
 	"testing"
 
@@ -241,3 +243,44 @@ func TestRunEqualsSyntax(t *testing.T) {
 		t.Fatal("unexpected error:", err)
 	}
 }
+
+func TestRunOutputEndsWithRawHex(t *testing.T) {
+	srv := fakeRPC(t, false)
+	defer srv.Close()
+
+	_, txHex := signedTestTx(t)
+
+	// Capture stdout to verify "Raw tx:" appears in output.
+	oldStdout := os.Stdout
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	os.Stdout = w
+
+	runErr := run([]string{"--rpc", srv.URL, txHex}, strings.NewReader(""))
+
+	w.Close()
+	os.Stdout = oldStdout
+
+	if runErr != nil {
+		t.Fatal("unexpected error:", runErr)
+	}
+
+	out, err := io.ReadAll(r)
+	if err != nil {
+		t.Fatal(err)
+	}
+	lines := strings.Split(strings.TrimSpace(string(out)), "\n")
+	lastLine := lines[len(lines)-1]
+
+	// The last line must be the raw hex transaction.
+	if !strings.HasPrefix(lastLine, "Raw tx: 0x") {
+		t.Fatalf("last output line = %q, want prefix \"Raw tx: 0x\"", lastLine)
+	}
+	// Verify the hex payload round-trips back to the input.
+	rawHex := strings.TrimPrefix(lastLine, "Raw tx: ")
+	if rawHex != txHex {
+		t.Fatalf("raw hex mismatch:\n got  %s\n want %s", rawHex, txHex)
+	}
+}