feat(build): Auto-detect base_ref from git merge-base (#2720)

Auto-detect base reference for build uploads using git merge-base.

Finds the merge-base commit SHA between HEAD and the remote tracking
branch (`refs/remotes/{remote}/HEAD`), eliminating the need to manually
specify --base-sha for most workflows.

In the future, we will add more checks for common CI providers to
automatically get this value as well.

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: runningcode

src/commands/build/upload.rs

@@ -24,7 +24,8 @@ use crate::utils::fs::TempDir;
 use crate::utils::fs::TempFile;
 use crate::utils::progress::ProgressBar;
 use crate::utils::vcs::{
-    self, get_provider_from_remote, get_repo_from_remote, git_repo_head_ref, git_repo_remote_url,
+    self, get_provider_from_remote, get_repo_from_remote, git_repo_base_ref, git_repo_head_ref,
+    git_repo_remote_url,
 };
 
 pub fn make_command(command: Command) -> Command {
@@ -79,7 +80,7 @@ pub fn make_command(command: Command) -> Command {
         .arg(
             Arg::new("base_ref")
                 .long("base-ref")
-                .help("The reference (branch) to use for the upload. If not provided, the current reference will be used.")
+                .help("The base reference (branch) to use for the upload. If not provided, the merge-base with the remote tracking branch will be used.")
         )
         .arg(
             Arg::new("pr_number")
@@ -113,7 +114,7 @@ pub fn execute(matches: &ArgMatches) -> Result<()> {
 
     let cached_remote = config.get_cached_vcs_remote();
     // Try to open the git repository and find the remote, but handle errors gracefully.
-    let (vcs_provider, head_repo_name, head_ref) = {
+    let (vcs_provider, head_repo_name, head_ref, base_ref) = {
         // Try to open the repo and get the remote URL, but don't fail if not in a repo.
         let repo = git2::Repository::open_from_env().ok();
         let repo_ref = repo.as_ref();
@@ -167,12 +168,32 @@ pub fn execute(matches: &ArgMatches) -> Result<()> {
                     .map(Cow::Owned)
             });
 
-        (vcs_provider, head_repo_name, head_ref)
+        let base_ref = matches
+            .get_one("base_ref")
+            .map(String::as_str)
+            .map(Cow::Borrowed)
+            .or_else(|| {
+                // Try to get the base ref from the VCS if not provided
+                // This attempts to find the merge-base with the remote tracking branch
+                repo_ref
+                    .and_then(|r| match git_repo_base_ref(r, &cached_remote) {
+                        Ok(base_ref_name) => {
+                            debug!("Found base reference: {}", base_ref_name);
+                            Some(base_ref_name)
+                        }
+                        Err(e) => {
+                            warn!("Could not detect base branch reference: {}", e);
+                            None
+                        }
+                    })
+                    .map(Cow::Owned)
+            });
+
+        (vcs_provider, head_repo_name, head_ref, base_ref)
     };
 
     let base_repo_name = matches.get_one("base_repo_name").map(String::as_str);
     let base_sha = matches.get_one("base_sha").map(String::as_str);
-    let base_ref = matches.get_one("base_ref").map(String::as_str);
     let pr_number = matches.get_one::<u32>("pr_number");
 
     let build_configuration = matches.get_one("build_configuration").map(String::as_str);
@@ -237,7 +258,7 @@ pub fn execute(matches: &ArgMatches) -> Result<()> {
             head_repo_name: head_repo_name.as_deref(),
             base_repo_name,
             head_ref: head_ref.as_deref(),
-            base_ref,
+            base_ref: base_ref.as_deref(),
             pr_number,
         };
         match upload_file(

src/utils/vcs.rs

@@ -249,6 +249,40 @@ pub fn git_repo_head_ref(repo: &git2::Repository) -> Result<String> {
     }
 }
 
+pub fn git_repo_base_ref(repo: &git2::Repository, remote_name: &str) -> Result<String> {
+    // Get the current HEAD commit
+    let head_commit = repo.head()?.peel_to_commit()?;
+
+    // Try to find the remote tracking branch
+    let remote_branch_name = format!("refs/remotes/{remote_name}/HEAD");
+    let remote_ref = repo.find_reference(&remote_branch_name).map_err(|e| {
+        anyhow::anyhow!(
+            "Could not find remote tracking branch for {}: {}",
+            remote_name,
+            e
+        )
+    })?;
+
+    find_merge_base_ref(repo, &head_commit, &remote_ref)
+}
+
+fn find_merge_base_ref(
+    repo: &git2::Repository,
+    head_commit: &git2::Commit,
+    remote_ref: &git2::Reference,
+) -> Result<String> {
+    let remote_commit = remote_ref.peel_to_commit()?;
+    let merge_base_oid = repo.merge_base(head_commit.id(), remote_commit.id())?;
+
+    // Return the merge-base commit SHA as the base reference
+    let merge_base_sha = merge_base_oid.to_string();
+    debug!(
+        "Found merge-base commit as base reference: {}",
+        merge_base_sha
+    );
+    Ok(merge_base_sha)
+}
+
 fn find_reference_url(repo: &str, repos: &[Repo]) -> Result<Option<String>> {
     let mut non_git = false;
     for configured_repo in repos {

tests/integration/_cases/build/build-upload-apk-all-uploaded.trycmd

@@ -2,6 +2,7 @@
 $ sentry-cli build upload tests/integration/_fixtures/build/apk.apk
 ? success
 [..]WARN[..]EXPERIMENTAL: The build subcommand is experimental. The command is subject to breaking changes and may be removed without notice in any release.
+  WARN    [..] Could not detect base branch reference: [..]
 Successfully uploaded 1 file to Sentry
   - tests/integration/_fixtures/build/apk.apk (http[..]/wat-org/preprod/wat-project/42)
 

tests/integration/_cases/build/build-upload-apk-no-token.trycmd

@@ -2,6 +2,7 @@
 $ sentry-cli build upload tests/integration/_fixtures/build/apk.apk
 ? failed
 [..]WARN[..]EXPERIMENTAL: The build subcommand is experimental. The command is subject to breaking changes and may be removed without notice in any release.
+  WARN    [..] Could not detect base branch reference: [..]
 error: Auth token is required for this request. Please run `sentry-cli login` and try again!
 
 Add --log-level=[info|debug] or export SENTRY_LOG_LEVEL=[info|debug] to see more output.

tests/integration/_cases/build/build-upload-apk.trycmd

@@ -2,6 +2,7 @@
 $ sentry-cli build upload tests/integration/_fixtures/build/apk.apk --head-sha test_head_sha
 ? success
 [..]WARN[..]EXPERIMENTAL: The build subcommand is experimental. The command is subject to breaking changes and may be removed without notice in any release.
+  WARN    [..] Could not detect base branch reference: [..]
 Successfully uploaded 1 file to Sentry
   - tests/integration/_fixtures/build/apk.apk (http[..]/wat-org/preprod/wat-project/42)
 

tests/integration/_cases/build/build-upload-help-macos.trycmd

@@ -42,8 +42,8 @@ Options:
           The reference (branch) to use for the upload. If not provided, the current reference will
           be used.
       --base-ref <base_ref>
-          The reference (branch) to use for the upload. If not provided, the current reference will
-          be used.
+          The base reference (branch) to use for the upload. If not provided, the merge-base with
+          the remote tracking branch will be used.
       --pr-number <pr_number>
           The pull request number to use for the upload. If not provided, the current pull request
           number will be used.

tests/integration/_cases/build/build-upload-help-not-macos.trycmd

@@ -41,8 +41,8 @@ Options:
           The reference (branch) to use for the upload. If not provided, the current reference will
           be used.
       --base-ref <base_ref>
-          The reference (branch) to use for the upload. If not provided, the current reference will
-          be used.
+          The base reference (branch) to use for the upload. If not provided, the merge-base with
+          the remote tracking branch will be used.
       --pr-number <pr_number>
           The pull request number to use for the upload. If not provided, the current pull request
           number will be used.

tests/integration/_cases/build/build-upload-ipa.trycmd

@@ -2,6 +2,7 @@
 $ sentry-cli build upload tests/integration/_fixtures/build/ipa.ipa --head-sha test_head_sha
 ? success
 [..]WARN[..]EXPERIMENTAL: The build subcommand is experimental. The command is subject to breaking changes and may be removed without notice in any release.
+  WARN    [..] Could not detect base branch reference: [..]
 Successfully uploaded 1 file to Sentry
   - tests/integration/_fixtures/build/ipa.ipa (http[..]/wat-org/preprod/wat-project/some-text-id)