Add the -v/--version option to show the version information

CHANGELOG.md

@@ -21,6 +21,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
    + Data representations preserve the ability to write to the original column and require no extra storage or complex triggers (compared to using `GENERATED ALWAYS` columns)
    + Note: data representations require Postgres 10 (Postgres 11 if using `IN` predicates); data representations are not implemented for RPC
  - #2647, Allow to verify the PostgREST version in SQL: `select distinct application_name from pg_stat_activity`. - @laurenceisla
+ - #2856, Add the `--version` CLI option that prints the version information - @laurenceisla
 
 ### Fixed
 

src/PostgREST/CLI.hs

@@ -80,14 +80,20 @@ readCLIShowHelp =
   where
     prefs = O.prefs $ O.showHelpOnError <> O.showHelpOnEmpty
     opts = O.info parser $ O.fullDesc <> progDesc
-    parser = O.helper <*> exampleParser <*> cliParser
+    parser = O.helper <*> versionFlag <*> exampleParser <*> cliParser
 
     progDesc =
       O.progDesc $
         "PostgREST "
         <> BS.unpack prettyVersion
         <> " / create a REST API to an existing Postgres database"
 
+    versionFlag =
+      O.infoOption ("PostgREST " <> BS.unpack prettyVersion) $
+        O.long "version"
+        <> O.short 'v'
+        <> O.help "Show the version information"
+
     exampleParser =
       O.infoOption exampleConfigFile $
         O.long "example"

test/io/fixtures.yaml

@@ -4,6 +4,10 @@ cli:
     args: ['--help']
   - name: help short
     args: ['-h']
+  - name: version long
+    args: ['--version']
+  - name: version short
+    args: ['-v']
   - name: example long
     args: ['--example']
   - name: example short