feat(cli): implement list command

... that returns list of directory with migration

migra-cli/src/config.rs

@@ -1,8 +1,7 @@
 use migra_core::path::PathBuilder;
 use serde::{Deserialize, Serialize};
-use std::fs;
-use std::io;
 use std::path::{Path, PathBuf};
+use std::{fs, io};
 
 const MIGRA_TOML_FILENAME: &str = "Migra.toml";
 
@@ -57,7 +56,7 @@ impl Config {
             Some(mut config_path) if config_path.is_dir() => {
                 config_path.push(MIGRA_TOML_FILENAME);
                 config_path
-            },
+            }
             Some(config_path) => config_path,
             None => recursive_find_config_file()?,
         };
@@ -88,3 +87,32 @@ impl Config {
         Ok(())
     }
 }
+
+impl Config {
+    pub fn directory_path(&self) -> PathBuf {
+        PathBuilder::from(&self.root)
+            .append(&self.directory)
+            .build()
+    }
+
+    pub fn migration_dirs(&self) -> io::Result<Vec<PathBuf>> {
+        let mut entries = self
+            .directory_path()
+            .read_dir()?
+            .map(|res| res.map(|e| e.path()))
+            .collect::<Result<Vec<_>, io::Error>>()?;
+
+        entries.sort();
+
+        let migration_dir_entries = entries
+            .into_iter()
+            .filter(|entry| {
+                entry.is_dir()
+                    && PathBuilder::from(entry).append("up.sql").build().exists()
+                    && PathBuilder::from(entry).append("down.sql").build().exists()
+            })
+            .collect::<Vec<_>>();
+
+        Ok(migration_dir_entries)
+    }
+}

migra-cli/src/main.rs

@@ -4,6 +4,7 @@ mod config;
 mod opts;
 
 use config::Config;
+use migra_core::path::PathBuilder;
 use opts::{AppOpt, ApplyCommandOpt, Command, StructOpt};
 use std::fs;
 
@@ -19,8 +20,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
             let mut client = migra_core::database::connect(&config.database.connection)?;
 
-            let file_path = migra_core::path::PathBuilder::from(config.root)
-                .append(config.directory)
+            let file_path = PathBuilder::from(config.directory_path())
                 .append(file_name)
                 .default_extension("sql")
                 .build();
@@ -36,7 +36,23 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                 }
             }
         }
-        Command::List | Command::Upgrade | Command::Downgrade => {
+        Command::List => {
+            let config = Config::read(opt.config)?;
+
+            let migration_dirs = config.migration_dirs()?;
+            if migration_dirs.is_empty() {
+                println!(
+                    "You haven't migrations in {}",
+                    config.directory_path().to_str().unwrap()
+                );
+            } else {
+                migration_dirs.iter().for_each(|dir| {
+                    let file_name = dir.file_name().and_then(|name| name.to_str()).unwrap();
+                    println!("{}", file_name);
+                });
+            }
+        }
+        Command::Upgrade | Command::Downgrade => {
             unimplemented!();
         }
     }