[#254] Revise dump-config command

Problem: xrefcheck does not allow to print the config to stdout instead
of writing it to a file. Also, it is easy to overwrite your changes by
mistake by executing the command again.

Solution: provide a --stdout flag to print the config to stdout, and do
not write it to a file unless a --force flag has been included.

exec/Main.hs

@@ -10,7 +10,8 @@ import Universum
 import Main.Utf8 (withUtf8)
 import System.IO.CodePage (withCP65001)
 
-import Xrefcheck.CLI (Command (..), getCommand)
+import System.Directory (doesFileExist)
+import Xrefcheck.CLI (Command (..), DumpConfigMode (..), getCommand)
 import Xrefcheck.Command (defaultAction)
 import Xrefcheck.Config (defConfigText)
 
@@ -20,5 +21,10 @@ main = withUtf8 $ withCP65001 $ do
   case command of
     DefaultCommand options ->
       defaultAction options
-    DumpConfig repoType path ->
+    DumpConfig repoType (DCMFile f path) -> do
+      whenM ((not f &&) <$> doesFileExist path) do
+        putTextLn "Output file exists. Use --force to overwrite."
+        exitFailure
       writeFile path (defConfigText repoType)
+    DumpConfig repoType DCMStdout ->
+      putStr (defConfigText repoType)

package.yaml

@@ -130,6 +130,7 @@ executables:
     dependencies:
       - xrefcheck
       - universum
+      - directory
       - with-utf8
       - code-page
 

src/Xrefcheck/CLI.hs

@@ -9,6 +9,7 @@ module Xrefcheck.CLI
   ( VerifyMode (..)
   , ExclusionOptions (..)
   , Command (..)
+  , DumpConfigMode (..)
   , Options (..)
   , NetworkingOptions (..)
 
@@ -70,7 +71,11 @@ modes =
 
 data Command
   = DefaultCommand Options
-  | DumpConfig Flavor FilePath
+  | DumpConfig Flavor DumpConfigMode
+
+data DumpConfigMode
+  = DCMFile Bool FilePath
+  | DCMStdout
 
 data Options = Options
   { oConfigPath        :: Maybe FilePath
@@ -218,7 +223,7 @@ dumpConfigOptions = hsubparser $
     info parser $
     progDesc "Dump default configuration into a file."
   where
-    parser = DumpConfig <$> repoTypeOption <*> outputOption
+    parser = DumpConfig <$> repoTypeOption <*> mode
 
     repoTypeOption =
       option repoTypeReadM $
@@ -239,6 +244,9 @@ dumpConfigOptions = hsubparser $
       value ".xrefcheck.yaml" <>
       help "Name of created config file."
 
+    mode = flag' DCMStdout (long "stdout")
+      <|> flag (DCMFile False) (DCMFile True) (long "force") <*> outputOption
+
 totalParser :: Parser Command
 totalParser = asum
   [ DefaultCommand <$> optionsParser

tests/golden/check-dump-config/.config.yaml

@@ -0,0 +1,3 @@
+# SPDX-FileCopyrightText: 2022 Serokell <https://serokell.io>
+#
+# SPDX-License-Identifier: MPL-2.0

tests/golden/check-dump-config/.xrefcheck.yaml

@@ -0,0 +1,3 @@
+# SPDX-FileCopyrightText: 2022 Serokell <https://serokell.io>
+#
+# SPDX-License-Identifier: MPL-2.0

tests/golden/check-dump-config/check-dump-config.bats

@@ -0,0 +1,67 @@
+#!/usr/bin/env bats
+
+# SPDX-FileCopyrightText: 2022 Serokell <https://serokell.io>
+#
+# SPDX-License-Identifier: MPL-2.0
+
+load '../helpers/bats-support/load'
+load '../helpers/bats-assert/load'
+load '../helpers/bats-file/load'
+load '../helpers'
+
+
+@test "Dump config to stdout" {
+  to_temp xrefcheck dump-config --stdout -t GitHub
+
+  assert_diff ../../configs/github-config.yaml
+}
+
+@test "Dump config to existent default file error" {
+  run xrefcheck dump-config -t GitHub
+
+  assert_failure
+
+  assert_output "Output file exists. Use --force to overwrite."
+}
+
+@test "Dump config to existent file error" {
+  run xrefcheck dump-config -o .config.yaml -t GitHub
+
+  assert_failure
+
+  assert_output "Output file exists. Use --force to overwrite."
+}
+
+@test "Dump config to non existent default file" {
+  cd $TEST_TEMP_DIR
+
+  run xrefcheck dump-config -t GitHub
+
+  assert_success
+}
+
+@test "Dump config to non existent file" {
+  cd $TEST_TEMP_DIR
+
+  run xrefcheck dump-config -o .config.yaml -t GitHub
+
+  assert_success
+}
+
+@test "Dump config to existent default file with force" {
+  cp .xrefcheck.yaml $TEST_TEMP_DIR
+  cd $TEST_TEMP_DIR
+
+  run xrefcheck dump-config -t GitHub --force
+
+  assert_success
+}
+
+@test "Dump config to existent file with force" {
+  cp .config.yaml $TEST_TEMP_DIR
+  cd $TEST_TEMP_DIR
+
+  run xrefcheck dump-config -o .config.yaml -t GitHub --force
+
+  assert_success
+}