Optionally use --changed-since for package selection

Author: Xanewok

src/cli.rs

@@ -67,8 +67,8 @@ pub struct PackageSelectOptions {
     /// and attempts to identify the packages and its dependents through that mechanism. You
     /// can use any `tag`, `branch` or `commit`, but you must be sure it is available
     /// (and up to date) locally.
-    #[structopt(short, long)]
-    pub changed_since: String,
+    #[structopt(short, long, name = "git-ref")]
+    pub changed_since: Option<String>,
 }
 
 #[derive(StructOpt, Debug)]
@@ -366,24 +366,15 @@ fn make_pkg_predicate(ws: &Workspace<'_>, args: PackageSelectOptions) -> Result<
                     .into(),
             );
         }
-        if changed_since.len() != 0 {
+        if changed_since.as_ref().map_or(false, |git_ref| !git_ref.is_empty()) {
             return Err(
                 "-p/--packages is mutually exlusive to using -c/--changed-since"
                     .into(),
             );
         }
     }
 
-    let publish = move |p: &Package| {
-        // If publish is set to false or any registry, it is ignored by default
-        // unless overriden.
-        let value = ignore_publish || p.publish().is_none();
-
-        trace!("{:}.publish={}", p.name(), value);
-        value
-    };
-
-    if changed_since.len() != 0 {
+    if changed_since.as_ref().map_or(false, |git_ref| !git_ref.is_empty()) {
         if !skip.is_empty() || !ignore_pre_version.is_empty() {
             return Err(
                 "-c/--changed-since is mutually exlusive to using -s/--skip and -i/--ignore-version-pre"
@@ -393,9 +384,29 @@ fn make_pkg_predicate(ws: &Workspace<'_>, args: PackageSelectOptions) -> Result<
 
     }
 
-    let changed = util::changed_packages(ws, &changed_since)?;
-    if changed.len() == 0 {
-        return Err("No changes detected".into())
+    // Either use explicitly given --packages or calculate packages that were
+    // --changed-since a given Git reference.
+    let packages = match changed_since {
+        Some(git_ref) if !git_ref.is_empty() => {
+            let changed = util::changed_packages(ws, &git_ref)?;
+
+            if changed.len() == 0 {
+                return Err("No changes detected".into())
+            };
+
+            changed.iter().map(Package::name).collect()
+        }
+        _ => packages,
+    };
+
+
+    let publish = move |p: &Package| {
+        // If publish is set to false or any registry, it is ignored by default
+        // unless overriden.
+        let value = ignore_publish || p.publish().is_none();
+
+        trace!("{:}.publish={}", p.name(), value);
+        value
     };
 
     if !packages.is_empty() {