[#104] Add maxRetries to configurable options

Problem: maxRetries option was hardcoded in source

Solution: Add it to verify options in config and make new CLI option to override count of retries

src/Xrefcheck/CLI.hs

@@ -27,7 +27,8 @@ import Data.Text qualified as T
 import Data.Version (showVersion)
 import Options.Applicative
   (Parser, ReadM, command, eitherReader, execParser, flag, flag', footerDoc, fullDesc, help, helper,
-  hsubparser, info, infoOption, long, metavar, option, progDesc, short, strOption, switch, value, OptionFields, Mod)
+  hsubparser, info, infoOption, long, metavar, option, progDesc, short, strOption, switch, value, auto,
+  OptionFields, Mod)
 import Options.Applicative.Help.Pretty (Doc, displayS, fill, fillSep, indent, renderPretty, text)
 
 import Paths_xrefcheck (version)
@@ -76,14 +77,16 @@ addTraversalOptions TraversalConfig{..} (TraversalOptions ignored) =
   , ..
   }
 
-newtype VerifyOptions = VerifyOptions
+data VerifyOptions = VerifyOptions
   { voCheckLocalhost :: Maybe Bool
+  , voMaxRetries     :: Maybe Int
   }
 
 addVerifyOptions :: VerifyConfig -> VerifyOptions -> VerifyConfig
-addVerifyOptions VerifyConfig{..} (VerifyOptions checkLocalhost) =
+addVerifyOptions VerifyConfig{..} (VerifyOptions checkLocalhost maxRetries) =
   VerifyConfig
   { vcCheckLocalhost = fromMaybe vcCheckLocalhost checkLocalhost
+  , vcMaxRetries = fromMaybe vcMaxRetries maxRetries
   , ..
   }
 
@@ -169,6 +172,12 @@ verifyOptionsParser = do
   voCheckLocalhost <- flag Nothing (Just True) $
     long "check-localhost" <>
     help "Check localhost links."
+  voMaxRetries <- option (Just <$> auto) $
+    long "retries" <>
+    metavar "INT" <>
+    value Nothing <>
+    help "How many attempts to retry an external link after getting \
+         \a \"429 Too Many Requests\" response."
   return VerifyOptions{..}
 
 dumpConfigOptions :: Parser Command

src/Xrefcheck/Config.hs

@@ -65,6 +65,7 @@ data VerifyConfig = VerifyConfig
   , vcDefaultRetryAfter         :: Time Second
     -- ^ Default Retry-After delay, applicable when we receive a 429 response
     -- and it does not contain a @Retry-After@ header.
+  , vcMaxRetries                :: Int
   }
 
 normaliseVerifyConfigFilePaths :: VerifyConfig -> VerifyConfig

src/Xrefcheck/Config/Default.hs

@@ -59,6 +59,10 @@ verification:
   # wait this amount of time before attempting to verify the link again.
   defaultRetryAfter: 30s
 
+  # How many attempts to retry an external link after getting
+  # a "429 Too Many Requests" response.
+  maxRetries: 3
+
 # Parameters of scanners for various file types.
 scanners:
   markdown:

src/Xrefcheck/Verify.hs

@@ -300,7 +300,7 @@ verifyReference
     retryVerification numberOfRetries resIO = do
       res@(VerifyResult ves) <- resIO
 
-      let toRetry = any isFixable ves && numberOfRetries < maxRetries
+      let toRetry = any isFixable ves && numberOfRetries < vcMaxRetries
           currentRetryAfter = extractRetryAfterInfo res
 
       let moveProgress = alterOverallProgress numberOfRetries
@@ -344,17 +344,17 @@ verifyReference
       -> Progress a
       -> Progress a
     alterProgressErrors res@(VerifyResult ves) retryNumber
-      | maxRetries == 0 =
+      | vcMaxRetries == 0 =
           if ok then id
           else incProgressUnfixableErrors
       | retryNumber == 0 =
           if ok then id
           else if fixable then incProgressFixableErrors
           else incProgressUnfixableErrors
-      | retryNumber == maxRetries =
+      | retryNumber == vcMaxRetries =
           if ok then decProgressFixableErrors
           else fixableToUnfixable
-      -- 0 < retryNumber < maxRetries
+      -- 0 < retryNumber < vcMaxRetries
       | otherwise =
           if ok then decProgressFixableErrors
           else if fixable then id
@@ -368,10 +368,6 @@ verifyReference
       VerifyResult [ExternalHttpTooManyRequests retryAfter] -> retryAfter
       _ -> vcDefaultRetryAfter
 
-    -- | Maximum number of retries available until a fixable error becomes unfixable.
-    -- Soon to become a configurable value.
-    maxRetries = 20
-
     checkRef mAnchor referredFile = verifying $ do
       checkReferredFileExists referredFile
       case M.lookup referredFile repoInfo of

tests/configs/github-config.yaml

@@ -50,6 +50,10 @@ verification:
   # wait this amount of time before attempting to verify the link again.
   defaultRetryAfter: 30s
 
+  # How many attempts to retry an external link after getting
+  # a "429 Too Many Requests" response.
+  maxRetries: 3
+
 # Parameters of scanners for various file types.
 scanners:
   markdown:

tests/golden/check-localhost/config-check-disabled.yaml

@@ -14,6 +14,7 @@ verification:
   checkLocalhost: false
   ignoreAuthFailures: true
   defaultRetryAfter: 30s
+  maxRetries: 3
 
 scanners:
   markdown:

tests/golden/check-localhost/config-check-enabled.yaml

@@ -14,6 +14,7 @@ verification:
   checkLocalhost: true
   ignoreAuthFailures: true
   defaultRetryAfter: 30s
+  maxRetries: 3
 
 scanners:
   markdown: