sq: Make input and output arguments reusable.

  - Extract input and output arguments, including help texts, so they
    can be easily reused by other sq subcommands.

  - This is part of the effort of moving to clap3's derive API and
    profit from the added type safety.

2 files changed, 26 insertions, 34 deletions

diff --git a/sq/src/sq.rs b/sq/src/sq.rs
index f08513c0..09565961 100644
--- a/sq/src/sq.rs
+++ b/sq/src/sq.rs
@@ -491,8 +491,8 @@ fn main() -> Result<()> {
             use clap::FromArgMatches;
             let command = sq_cli::SignCommand::from_arg_matches(m)?;
 
-            let mut input = open_or_stdin(command.input.as_deref())?;
-            let output = command.output.as_deref();
+            let mut input = open_or_stdin(command.io.input.as_deref())?;
+            let output = command.io.output.as_deref();
             let detached = command.detached;
             let binary = command.binary;
             let append = command.append;
@@ -560,9 +560,9 @@ fn main() -> Result<()> {
             let command = sq_cli::VerifyCommand::from_arg_matches(m)?;
 
             // TODO: Fix interface of open_or_stdin, create_or_stdout_safe, etc.
-            let mut input = open_or_stdin(command.input.as_deref())?;
+            let mut input = open_or_stdin(command.io.input.as_deref())?;
             let mut output =
-                config.create_or_stdout_safe(command.output.as_deref())?;
+                config.create_or_stdout_safe(command.io.output.as_deref())?;
             let mut detached = if let Some(f) = command.detached {
                 Some(File::open(f)?)
             } else {
@@ -634,9 +634,9 @@ fn main() -> Result<()> {
             use clap::FromArgMatches;
             let command = sq_cli::DearmorCommand::from_arg_matches(m)?;
 
-            let mut input = open_or_stdin(command.input.as_deref())?;
+            let mut input = open_or_stdin(command.io.input.as_deref())?;
             let mut output =
-                config.create_or_stdout_safe(command.output.as_deref())?;
+                config.create_or_stdout_safe(command.io.output.as_deref())?;
             let mut filter = armor::Reader::from_reader(&mut input, None);
             io::copy(&mut filter, &mut output)?;
         },
diff --git a/sq/src/sq_cli.rs b/sq/src/sq_cli.rs
index 06e830a3..1b328612 100644
--- a/sq/src/sq_cli.rs
+++ b/sq/src/sq_cli.rs
@@ -1,5 +1,5 @@
 /// Command-line parser for sq.
-use clap::{Arg, ArgGroup, Command, ArgEnum};
+use clap::{Arg, ArgGroup, Command, ArgEnum, Args};
 use clap::{CommandFactory, Parser};
 
 pub fn build() -> Command<'static> {
@@ -1716,6 +1716,19 @@ $ sq autocrypt encode-sender --prefer-encrypt mutual juliet.pgp
     app
 }
 
+#[derive(Debug, Args)]
+pub struct IoArgs {
+    #[clap(value_name = "FILE", help = "Reads from FILE or stdin if omitted")]
+    pub input: Option<String>,
+    #[clap(
+        short,
+        long,
+        value_name = "FILE",
+        help = "Writes to FILE or stdout if omitted"
+    )]
+    pub output: Option<String>,
+}
+
 // TODO?: Option<_> conflicts with default value
 // TODO: Use PathBuf as input type for more type safety? Investigate conversion
 // TODO: use indoc to transparently (de-)indent static strings
@@ -1818,15 +1831,8 @@ $ sq dearmor ascii-message.pgp
 ",
     )]
 pub struct DearmorCommand {
-    #[clap(value_name = "FILE", help = "Reads from FILE or stdin if omitted")]
-    pub input: Option<String>,
-    #[clap(
-        short,
-        long,
-        value_name = "FILE",
-        help = "Writes to FILE or stdout if omitted"
-    )]
-    pub output: Option<String>,
+    #[clap(flatten)]
+    pub io: IoArgs,
 }
 
 #[derive(Parser, Debug)]
@@ -1868,15 +1874,8 @@ signatures, consider using sequoia-sqv.
 ",
     )]
 pub struct VerifyCommand {
-    #[clap(value_name = "FILE", help = "Reads from FILE or stdin if omitted")]
-    pub input: Option<String>,
-    #[clap(
-        short,
-        long,
-        value_name = "FILE",
-        help = "Writes to FILE or stdout if omitted"
-    )]
-    pub output: Option<String>,
+    #[clap(flatten)]
+    pub io: IoArgs,
     #[clap(
         long = "detached",
         value_name = "SIG",
@@ -1931,15 +1930,8 @@ $ sq sign --detached --signer-key juliet.pgp message.txt
 ",
     )]
 pub struct SignCommand {
-    #[clap(value_name = "FILE", help = "Reads from FILE or stdin if omitted")]
-    pub input: Option<String>,
-    #[clap(
-        short,
-        long,
-        value_name = "FILE",
-        help = "Writes to FILE or stdout if omitted"
-    )]
-    pub output: Option<String>,
+    #[clap(flatten)]
+    pub io: IoArgs,
     // TODO: Why capital B?
     #[clap(
         short = 'B',