added rollup mode management

Author: geetanshjuneja

.sqlx/query-ad1e4676b67caa18bd10c4d9e727950e437d538a747b18ecbf1206ef6b148dc9.json renamed to .sqlx/query-7efe43b9bd54cc798a81cfe8c4a1ef396044c382b6f5172fb389175d8ce1346e.json

@@ -0,0 +1,2 @@
+-- Add up migration script here
+ALTER TABLE pull_request DROP COLUMN rollup;

.sqlx/query-a7498731ebc2ae95a48c52046eb9377656acd7bb2907000abcbee1c7ce90ad43.json

@@ -0,0 +1,2 @@
+-- Add up migration script here
+ALTER TABLE pull_request ADD COLUMN rollup TEXT;

.sqlx/query-c4b0d4ed216c6b8efceb1b65ae0ad9d830e8870cfdf37542a408b99c961318f7.json renamed to .sqlx/query-aaceccc739564492d8424e6951f9c272c88dd4d34199c7ee4346462867029823.json

@@ -1,4 +1,7 @@
 mod parser;
+use std::fmt;
+use std::str::FromStr;
+
 use crate::github::CommitSha;
 pub use parser::{CommandParseError, CommandParser};
 
@@ -22,6 +25,42 @@ pub enum Approver {
     Specified(String),
 }
 
+const ROLLUP_VALUES: [&str; 4] = ["always", "iffy", "maybe", "never"];
+
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum RollupMode {
+    Always,
+    Iffy,
+    Maybe,
+    Never,
+}
+
+impl fmt::Display for RollupMode {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let s = match self {
+            RollupMode::Always => "always",
+            RollupMode::Iffy => "iffy",
+            RollupMode::Never => "never",
+            RollupMode::Maybe => "maybe",
+        };
+        write!(f, "{}", s)
+    }
+}
+
+impl FromStr for RollupMode {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "always" => Ok(RollupMode::Always),
+            "iffy" => Ok(RollupMode::Iffy),
+            "never" => Ok(RollupMode::Never),
+            "maybe" => Ok(RollupMode::Maybe),
+            _ => Err(()),
+        }
+    }
+}
+
 /// Bors command specified by a user.
 #[derive(Debug, PartialEq)]
 pub enum BorsCommand {
@@ -31,6 +70,8 @@ pub enum BorsCommand {
         approver: Approver,
         /// Priority of the commit.
         priority: Option<Priority>,
+        // Rollup status of the commit.
+        rollup: Option<RollupMode>,
     },
     /// Unapprove a commit.
     Unapprove,
@@ -53,4 +94,6 @@ pub enum BorsCommand {
     Delegate,
     /// Revoke any previously granted delegation.
     Undelegate,
+    /// Rollup status.
+    Rollup(RollupMode),
 }