refactor: hand clap's own structs to the commands

src/commands/postgres.rs

@@ -10,6 +10,7 @@ use anyhow::{Context, Result, bail};
 use self::server::{Database, wait_until_ready, when_ready};
 use self::shape::{Dump, HEADER_LEN, Kind};
 use crate::cli::Format;
+use crate::cli::postgres as cli;
 use crate::cmd::{
     Cmd, Cp, CreateDb, DropDb, Gunzip, Gzip, Head, PgDump, PgDumpAll, PgRestore, Psql, Rm,
 };
@@ -297,10 +298,13 @@ pub fn psql(ctx: &Ctx, rest: &[String]) -> Result<()> {
         .replace(ctx)
 }
 
-pub fn dump(ctx: &Ctx, file: &Path, format: Format, gzip: bool) -> Result<()> {
+pub fn dump(ctx: &Ctx, args: &cli::Dump) -> Result<()> {
+    let (file, format, gzip) = (args.path.as_path(), args.format, args.gzip);
     let db = Database::resolve(ctx)?;
 
     if format == Format::Directory {
+        // main says this as an argument error before getting here; kept as the
+        // last word in case anything else ever calls dump
         if gzip {
             bail!("a directory dump is a directory of already compressed files, not a stream");
         }
@@ -343,8 +347,8 @@ pub fn dump(ctx: &Ctx, file: &Path, format: Format, gzip: bool) -> Result<()> {
 
 // pg_dump for one database, pg_dumpall for a cluster, which has no format letter
 fn dump_command(db: &Database, format: Format) -> Box<dyn Cmd + '_> {
-    match format.flag() {
-        Some(flag) => Box::new(PgDump::new(&db.user, &db.name, flag)),
+    match PgDump::of(&db.user, &db.name, format) {
+        Some(dump) => Box::new(dump),
         None => Box::new(PgDumpAll { username: &db.user }),
     }
 }
@@ -364,7 +368,8 @@ fn dump_directory(ctx: &Ctx, db: &Database, target: &Path) -> Result<()> {
     note!(ctx, "dumping to local directory {}", target.display());
     let remote = remote_dump();
 
-    PgDump::new(&db.user, &db.name, "d")
+    PgDump::of(&db.user, &db.name, Format::Directory)
+        .expect("a directory dump has a pg_dump letter")
         .to(&remote)
         .in_container(&db.container)
         .run(ctx)?;