allow saving the bench report to an arbitrary location

agora-bench/Main.hs

@@ -4,6 +4,7 @@ import Bench (specificationTreeToBenchmarks)
 import Data.Csv (encodeDefaultOrderedByName)
 import Data.Text.Lazy.Encoding (decodeUtf8)
 import Data.Text.Lazy.IO as I (writeFile)
+import Options (Options (..), parseOptions)
 import Prettyprinter (defaultLayoutOptions, layoutPretty, pretty)
 import Prettyprinter.Render.String (renderString)
 import Spec.AuthorityToken qualified as AuthorityToken
@@ -20,7 +21,9 @@ import Prelude
 
 main :: IO ()
 main = do
-  I.writeFile "bench.csv" $
+  options <- parseOptions
+
+  I.writeFile options.output $
     (decodeUtf8 . encodeDefaultOrderedByName) res
 
   mapM_ (putStrLn . renderString . layoutPretty defaultLayoutOptions . pretty) res

agora-bench/Options.hs

@@ -0,0 +1,31 @@
+module Options (Options (..), parseOptions) where
+
+import Options.Applicative ((<**>))
+import Options.Applicative qualified as Opt
+
+newtype Options = Options
+  { output :: FilePath
+  }
+
+outputOpt :: Opt.Parser FilePath
+outputOpt =
+  Opt.strOption
+    ( Opt.long "output-path"
+        <> Opt.short 'o'
+        <> Opt.metavar "OUTPUT_PATH"
+        <> Opt.value "./bench.csv"
+        <> Opt.help "The path of the bench report file."
+    )
+
+benchOpt :: Opt.Parser Options
+benchOpt = Options <$> outputOpt
+
+parseOptions :: IO Options
+parseOptions = Opt.execParser p
+  where
+    p =
+      Opt.info
+        (benchOpt <**> Opt.helper)
+        ( Opt.fullDesc
+            <> Opt.progDesc "Generate benchmark report of agora scripts"
+        )

agora.cabal

@@ -212,13 +212,17 @@ benchmark agora-bench
   import:         lang, deps
   hs-source-dirs: agora-bench
   main-is:        Main.hs
-  other-modules:  Bench
+  other-modules:
+    Bench
+    Options
+
   type:           exitcode-stdio-1.0
   build-depends:
     , agora
     , agora-sample
     , agora-spec
     , cassava
+    , optparse-applicative
 
 executable agora-scripts
   import:         lang, deps, exe-opts