feat: add priority

Author: Sakib25800

.sqlx/query-6410d5ac20c9b301fc7b9e639eabc7b82a2a1d01cde48ba01fdc5cd8ce2ce128.json .sqlx/query-491dd6278535e1015a8071f416a56112a153713a71af8d62917e2ff9873ecec1.json

@@ -8,3 +8,4 @@ which is by default set to `@bors`.
 | `try`              | `try`           | Start a try build based on the most recent commit from the main branch. |
 | `try parent=<sha>` | `try`           | Start a try build based on the specified parent commit `sha`.           |
 | `try cancel`       | `try`           | Cancel a running try build.                                             |
+| `p=<priority>`     | `try`           | Set the priority of a PR.                                               |

.sqlx/query-667daf4042d6129c923d1f8f6b1b19d263ad3a242cbf60841d1284da702b78ff.json

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

.sqlx/query-9531efa35aabadfb04c06f23375eafe1c8f10444e706940fa0f20a50b824044d.json .sqlx/query-67511f5f15c07537d3d4f2d011abedd2173ab301e8a06c740b587738b140795a.json

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

.sqlx/query-7a9718cb973d09f68a6854a4fb08871f29d60b8617caf94dfa439f9ef8453caa.json

@@ -2,6 +2,9 @@ mod parser;
 use crate::github::CommitSha;
 pub use parser::{CommandParseError, CommandParser};
 
+/// Priority of a commit.
+pub type Priority = u32;
+
 /// Type of parent allowed in a try build
 #[derive(Clone, Debug, PartialEq)]
 pub enum Parent {
@@ -23,10 +26,15 @@ pub enum Approver {
 #[derive(Debug, PartialEq)]
 pub enum BorsCommand {
     /// Approve a commit.
-    Approve(Approver),
+    Approve {
+        /// Who is approving the commit.
+        approver: Approver,
+        /// Priority of the commit.
+        priority: Option<Priority>,
+    },
     /// Unapprove a commit.
     Unapprove,
-    /// Print help
+    /// Print help.
     Help,
     /// Ping the bot.
     Ping,
@@ -39,4 +47,6 @@ pub enum BorsCommand {
     },
     /// Cancel a try build.
     TryCancel,
+    /// Set the priority of a commit.
+    SetPriority(Priority),
 }