Sort MCP server environment variables alphabetically during workflow compilation (#1302)

* Initial plan

* Sort MCP env vars alphabetically during compilation

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Recompile workflows with sorted env vars

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Add test for MCP env var alphabetical sorting

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Sort MCP server environment variables alphabetically during workflow compilation

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* sort envs

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>
Co-authored-by: Peli de Halleux <pelikhan@users.noreply.github.com>

Author: Copilot

.github/workflows/duplicate-code-detector.lock.yml

@@ -2,6 +2,7 @@ package workflow
 
 import (
 	"fmt"
+	"sort"
 	"strings"
 
 	"github.com/githubnext/gh-aw/pkg/console"
@@ -183,13 +184,16 @@ func renderSharedMCPConfig(yaml *strings.Builder, toolName string, toolConfig ma
 		case "env":
 			if renderer.Format == "toml" {
 				fmt.Fprintf(yaml, "%senv = { ", renderer.IndentLevel)
-				first := true
-				for envKey, envValue := range mcpConfig.Env {
-					if !first {
+				envKeys := make([]string, 0, len(mcpConfig.Env))
+				for key := range mcpConfig.Env {
+					envKeys = append(envKeys, key)
+				}
+				sort.Strings(envKeys)
+				for i, envKey := range envKeys {
+					if i > 0 {
 						yaml.WriteString(", ")
 					}
-					fmt.Fprintf(yaml, "\"%s\" = \"%s\"", envKey, envValue)
-					first = false
+					fmt.Fprintf(yaml, "\"%s\" = \"%s\"", envKey, mcpConfig.Env[envKey])
 				}
 				yaml.WriteString(" }\n")
 			} else {
@@ -202,6 +206,7 @@ func renderSharedMCPConfig(yaml *strings.Builder, toolName string, toolConfig ma
 				for key := range mcpConfig.Env {
 					envKeys = append(envKeys, key)
 				}
+				sort.Strings(envKeys)
 				for envIndex, envKey := range envKeys {
 					envComma := ","
 					if envIndex == len(envKeys)-1 {
@@ -227,6 +232,7 @@ func renderSharedMCPConfig(yaml *strings.Builder, toolName string, toolConfig ma
 			for key := range mcpConfig.Headers {
 				headerKeys = append(headerKeys, key)
 			}
+			sort.Strings(headerKeys)
 			for headerIndex, headerKey := range headerKeys {
 				headerComma := ","
 				if headerIndex == len(headerKeys)-1 {

pkg/workflow/mcp-config.go

@@ -116,6 +116,87 @@ Please use the markitdown MCP server to convert HTML to markdown.
 	}
 }
 
+// TestMCPEnvVarsAlphabeticallySorted verifies that env vars in MCP configs are sorted alphabetically
+func TestMCPEnvVarsAlphabeticallySorted(t *testing.T) {
+	// Create a temporary markdown file with mcp-servers configuration containing env vars
+	workflowContent := `---
+on:
+  workflow_dispatch:
+permissions:
+  contents: read
+engine: copilot
+mcp-servers:
+  test-server:
+    container: example/test:latest
+    env:
+      ZEBRA_VAR: "z"
+      ALPHA_VAR: "a"
+      BETA_VAR: "b"
+---
+
+# Test MCP Env Var Sorting
+
+This workflow tests that MCP server env vars are sorted alphabetically.
+`
+
+	// Create temporary file
+	tmpFile, err := os.CreateTemp("", "test-env-sort-*.md")
+	if err != nil {
+		t.Fatalf("Failed to create temp file: %v", err)
+	}
+	defer os.Remove(tmpFile.Name())
+
+	// Write content to file
+	if _, err := tmpFile.WriteString(workflowContent); err != nil {
+		t.Fatalf("Failed to write to temp file: %v", err)
+	}
+	tmpFile.Close()
+
+	// Create compiler and compile workflow
+	compiler := NewCompiler(false, "", "test")
+	compiler.SetSkipValidation(true)
+
+	// Generate YAML
+	workflowData, err := compiler.ParseWorkflowFile(tmpFile.Name())
+	if err != nil {
+		t.Fatalf("Failed to parse workflow file: %v", err)
+	}
+
+	yamlContent, err := compiler.generateYAML(workflowData, tmpFile.Name())
+	if err != nil {
+		t.Fatalf("Failed to generate YAML: %v", err)
+	}
+
+	// Find the env section in the generated YAML
+	envIndex := strings.Index(yamlContent, `"env": {`)
+	if envIndex == -1 {
+		t.Fatalf("Could not find env section in generated YAML")
+	}
+
+	// Extract a portion of YAML starting from env section (next 300 chars should be enough)
+	envSection := yamlContent[envIndex : envIndex+300]
+
+	// Verify that ALPHA_VAR appears before BETA_VAR and ZEBRA_VAR
+	alphaIndex := strings.Index(envSection, `"ALPHA_VAR"`)
+	betaIndex := strings.Index(envSection, `"BETA_VAR"`)
+	zebraIndex := strings.Index(envSection, `"ZEBRA_VAR"`)
+
+	if alphaIndex == -1 || betaIndex == -1 || zebraIndex == -1 {
+		t.Fatalf("Could not find all env vars in generated YAML. Section: %s", envSection)
+	}
+
+	// Verify alphabetical order
+	if alphaIndex >= betaIndex {
+		t.Errorf("Expected ALPHA_VAR to appear before BETA_VAR, but ALPHA_VAR is at %d and BETA_VAR is at %d", alphaIndex, betaIndex)
+	}
+	if betaIndex >= zebraIndex {
+		t.Errorf("Expected BETA_VAR to appear before ZEBRA_VAR, but BETA_VAR is at %d and ZEBRA_VAR is at %d", betaIndex, zebraIndex)
+	}
+	if alphaIndex >= zebraIndex {
+		t.Errorf("Expected ALPHA_VAR to appear before ZEBRA_VAR, but ALPHA_VAR is at %d and ZEBRA_VAR is at %d", alphaIndex, zebraIndex)
+	}
+}
+
 // TestHasMCPConfigDetection verifies that hasMCPConfig properly detects MCP configurations
 func TestHasMCPConfigDetection(t *testing.T) {
 	testCases := []struct {