fix(doctor): print each check group as it completes

Every group was collected before anything was printed, so one slow check
withheld the entire report including groups that had already passed. Order,
formatting, summary and exit codes are unchanged.

Author: kolaente

pkg/cmd/doctor.go

@@ -53,9 +53,11 @@ Exit codes:
 		config.InitConfig()
 	},
 	Run: func(_ *cobra.Command, _ []string) {
-		results := doctor.Run()
+		doctor.PrintHeader(os.Stdout)
 
-		doctor.PrintResults(os.Stdout, results)
+		results := doctor.Run(func(group doctor.CheckGroup) {
+			doctor.PrintGroup(os.Stdout, group)
+		})
 
 		failed := doctor.CountFailed(results)
 		if failed > 0 {

pkg/doctor/doctor.go

@@ -17,17 +17,22 @@
 // Package doctor provides diagnostic checks for Vikunja installations.
 package doctor
 
-// Run executes all diagnostic checks and returns the results.
-func Run() []CheckGroup {
-	groups := []CheckGroup{
-		CheckSystem(),
-		CheckConfig(),
-		CheckDatabase(),
-		CheckFiles(),
+// Run executes all diagnostic checks in order and returns the results. Each group is
+// passed to emit as soon as it completes, so a slow check does not withhold the
+// groups before it.
+func Run(emit func(CheckGroup)) []CheckGroup {
+	var groups []CheckGroup
+	collect := func(group CheckGroup) {
+		groups = append(groups, group)
+		emit(group)
 	}
 
-	// Add optional service checks
-	groups = append(groups, CheckOptionalServices()...)
+	collect(CheckSystem())
+	collect(CheckConfig())
+	collect(CheckDatabase())
+	collect(CheckFiles())
+
+	CheckOptionalServices(collect)
 
 	return groups
 }

pkg/doctor/output.go

@@ -29,19 +29,20 @@ var (
 	bold       = color.New(color.Bold).SprintFunc()
 )
 
-// PrintResults writes all check groups to the given writer with colored output.
-func PrintResults(w io.Writer, groups []CheckGroup) {
+// PrintHeader writes the report header to the given writer.
+func PrintHeader(w io.Writer) {
 	fmt.Fprintln(w, bold("Vikunja Doctor"))
 	fmt.Fprintln(w, "==============")
 	fmt.Fprintln(w)
+}
 
-	for _, group := range groups {
-		fmt.Fprintln(w, bold(group.Name))
-		for _, result := range group.Results {
-			printResult(w, result)
-		}
-		fmt.Fprintln(w)
+// PrintGroup writes a single check group to the given writer with colored output.
+func PrintGroup(w io.Writer, group CheckGroup) {
+	fmt.Fprintln(w, bold(group.Name))
+	for _, result := range group.Results {
+		printResult(w, result)
 	}
+	fmt.Fprintln(w)
 }
 
 func printResult(w io.Writer, result CheckResult) {

pkg/doctor/output_test.go

@@ -0,0 +1,50 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package doctor
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPrintGroup(t *testing.T) {
+	var buf bytes.Buffer
+
+	PrintHeader(&buf)
+	PrintGroup(&buf, CheckGroup{
+		Name: "Files (s3)",
+		Results: []CheckResult{
+			{Name: "Endpoint", Passed: true, Value: "http://localhost:9000"},
+			{Name: "Initialization", Passed: false, Error: "S3 endpoint http://localhost:9000 did not respond within 12s"},
+			{Name: "CORS", Passed: true, Value: "2 origins", Lines: []string{"a", "b"}},
+		},
+	})
+
+	assert.Equal(t, `Vikunja Doctor
+==============
+
+Files (s3)
+  ✓ Endpoint: http://localhost:9000
+  ✗ Initialization: S3 endpoint http://localhost:9000 did not respond within 12s
+  ✓ CORS: 2 origins
+      a
+      b
+
+`, buf.String())
+}

pkg/doctor/services.go

@@ -31,27 +31,24 @@ import (
 	"code.vikunja.io/api/pkg/red"
 )
 
-// CheckOptionalServices returns check groups for all enabled optional services.
-func CheckOptionalServices() []CheckGroup {
-	var groups []CheckGroup
-
+// CheckOptionalServices runs the checks for all enabled optional services, passing
+// each group to emit as it completes.
+func CheckOptionalServices(emit func(CheckGroup)) {
 	if config.RedisEnabled.GetBool() {
-		groups = append(groups, checkRedis())
+		emit(checkRedis())
 	}
 
 	if config.MailerEnabled.GetBool() {
-		groups = append(groups, checkMailer())
+		emit(checkMailer())
 	}
 
 	if config.AuthLdapEnabled.GetBool() {
-		groups = append(groups, checkLDAP())
+		emit(checkLDAP())
 	}
 
 	if config.AuthOpenIDEnabled.GetBool() {
-		groups = append(groups, checkOpenID())
+		emit(checkOpenID())
 	}
-
-	return groups
 }
 
 func checkRedis() CheckGroup {