From dfc6fb3c83d1ee1eff9d3f3731747a8e92f29718 Mon Sep 17 00:00:00 2001
From: Cody Ley-Han <codyleyhan@gmail.com>
Date: Wed, 4 Sep 2019 23:29:38 -0700
Subject: [PATCH] Add user supplied error messages in depguard issues

---
 .golangci.yml                      |  2 ++
 README.md                          |  2 ++
 pkg/config/config.go               |  7 ++++---
 pkg/golinters/depguard.go          | 22 +++++++++++++++++++++-
 test/testdata/configs/depguard.yml |  7 +++++++
 test/testdata/depguard.go          |  5 ++---
 6 files changed, 38 insertions(+), 7 deletions(-)
 create mode 100644 test/testdata/configs/depguard.yml

diff --git a/.golangci.yml b/.golangci.yml
index 85b508e6c6c0..1c20e737a3a6 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -25,6 +25,8 @@ linters-settings:
       # logging is allowed only by logutils.Log, logrus
       # is allowed to use only in logutils package
       - github.com/sirupsen/logrus
+    packages-with-error-messages:
+      github.com/sirupsen/logrus: "logging is allowed only by logutils.Log"
   misspell:
     locale: US
   lll:
diff --git a/README.md b/README.md
index e7f4be6bbc51..72f324226ec6 100644
--- a/README.md
+++ b/README.md
@@ -837,6 +837,8 @@ linters-settings:
       # logging is allowed only by logutils.Log, logrus
       # is allowed to use only in logutils package
       - github.com/sirupsen/logrus
+    packages-with-error-messages:
+      github.com/sirupsen/logrus: "logging is allowed only by logutils.Log"
   misspell:
     locale: US
   lll:
diff --git a/pkg/config/config.go b/pkg/config/config.go
index 9a113fe6d892..e9dd3be2c2ca 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -153,9 +153,10 @@ type LintersSettings struct {
 		MinOccurrencesCount int `mapstructure:"min-occurrences"`
 	}
 	Depguard struct {
-		ListType      string `mapstructure:"list-type"`
-		Packages      []string
-		IncludeGoRoot bool `mapstructure:"include-go-root"`
+		ListType                 string `mapstructure:"list-type"`
+		Packages                 []string
+		IncludeGoRoot            bool              `mapstructure:"include-go-root"`
+		PackagesWithErrorMessage map[string]string `mapstructure:"packages-with-error-message"`
 	}
 	Misspell struct {
 		Locale      string
diff --git a/pkg/golinters/depguard.go b/pkg/golinters/depguard.go
index a00af5c9f1ac..d3760bfbbbe9 100644
--- a/pkg/golinters/depguard.go
+++ b/pkg/golinters/depguard.go
@@ -36,6 +36,22 @@ func (d Depguard) Run(ctx context.Context, lintCtx *linter.Context) ([]result.Is
 		dg.ListType = depguardAPI.LTBlacklist
 	}
 
+	if dg.ListType == depguardAPI.LTBlacklist {
+		// if the list type was a blacklist the packages with error messages should
+		// be included in the blacklist package list
+
+		noMessagePackages := make(map[string]bool)
+		for _, pkg := range dg.Packages {
+			noMessagePackages[pkg] = true
+		}
+
+		for pkg := range lintCtx.Settings().Depguard.PackagesWithErrorMessage {
+			if _, ok := noMessagePackages[pkg]; !ok {
+				dg.Packages = append(dg.Packages, pkg)
+			}
+		}
+	}
+
 	issues, err := dg.Run(lintCtx.LoaderConfig, lintCtx.Program)
 	if err != nil {
 		return nil, err
@@ -49,9 +65,13 @@ func (d Depguard) Run(ctx context.Context, lintCtx *linter.Context) ([]result.Is
 	}
 	res := make([]result.Issue, 0, len(issues))
 	for _, i := range issues {
+		userSuppliedMsgSuffix := lintCtx.Settings().Depguard.PackagesWithErrorMessage[i.PackageName]
+		if userSuppliedMsgSuffix != "" {
+			userSuppliedMsgSuffix = ": " + userSuppliedMsgSuffix
+		}
 		res = append(res, result.Issue{
 			Pos:        i.Position,
-			Text:       fmt.Sprintf("%s %s", formatCode(i.PackageName, lintCtx.Cfg), msgSuffix),
+			Text:       fmt.Sprintf("%s %s%s", formatCode(i.PackageName, lintCtx.Cfg), msgSuffix, userSuppliedMsgSuffix),
 			FromLinter: d.Name(),
 		})
 	}
diff --git a/test/testdata/configs/depguard.yml b/test/testdata/configs/depguard.yml
new file mode 100644
index 000000000000..aa06e3ee9e61
--- /dev/null
+++ b/test/testdata/configs/depguard.yml
@@ -0,0 +1,7 @@
+linters-settings:
+  depguard:
+    include-go-root: true
+    packages: 
+      - compress/*
+    packages-with-error-message:
+      log: "don't use log"
diff --git a/test/testdata/depguard.go b/test/testdata/depguard.go
index 7613fc7a3267..e1ab70613be0 100644
--- a/test/testdata/depguard.go
+++ b/test/testdata/depguard.go
@@ -1,11 +1,10 @@
 //args: -Edepguard
-//config: linters-settings.depguard.include-go-root=true
-//config: linters-settings.depguard.packages=compress/*,log
+//config_path: testdata/configs/depguard.yml
 package testdata
 
 import (
 	"compress/gzip" // ERROR "`compress/gzip` is in the blacklist"
-	"log"           // ERROR "`log` is in the blacklist"
+	"log"           // ERROR "`log` is in the blacklist: don't use log"
 )
 
 func SpewDebugInfo() {