feat: adding error on no commits in range

Author: DeveloperC286

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "conventional_commits_linter"
-version = "0.9.0"
+version = "0.10.0"
 description = "A tooling and language agnostic utility to lint Git commits against the Conventional Commits specification."
 authors = ["C <DeveloperC@protonmail.com>"]
 edition = "2021"
@@ -26,7 +26,7 @@ git2 = { version = "0.13.25", default-features = false, features=[] }
 strum = "0.23.0"
 strum_macros = "0.23.1"
 
-conventional_commits_linter_lib = "0.1.0"
+conventional_commits_linter_lib = "0.2.0"
 
 
 [dev-dependencies]

conventional_commits_linter/Cargo.toml

@@ -0,0 +1,12 @@
+Feature: When the range of commits from to lint are empty, then an error is returned.
+
+
+  Scenario Outline:
+    Given the repository "<repository>" is cloned and checked out at the commit "<checkout_commit>".
+    When the argument --from-commit-hash is provided as "<checkout_commit>".
+    Then their is a no commits error.
+
+
+    Examples:
+      | repository                                    | checkout_commit                          |
+      | https://github.com/danielduarte/diffparse.git | df6be23b79af66d3684fb27719020e1ce587f4b8 |

conventional_commits_linter/end-to-end-tests/features/no-commits.feature

@@ -141,3 +141,15 @@ def then_ambiguous_shortened_commit_hash_error(context, shortened_commit_hash):
     # Then
     assert ambiguous_shortened_commit_hash_error.match(
         context.stderr) is not None
+
+
+@then('their is a no commits error.')
+def then_no_commits_error(context):
+    # Given
+    no_commits_error = " ERROR conventional_commits_linter_lib::commits > No Git commits within the provided range.\n"
+
+    # When/Then
+    then_linting_fails(context)
+
+    # Then
+    assert context.stderr == no_commits_error

conventional_commits_linter/end-to-end-tests/features/steps/then.py

@@ -1,6 +1,6 @@
 [package]
 name = "conventional_commits_linter_lib"
-version = "0.1.0"
+version = "0.2.0"
 description = "A tooling and language agnostic library to lint Git commits against the Conventional Commits specification."
 authors = ["C <DeveloperC@protonmail.com>"]
 edition = "2021"

conventional_commits_linter_lib/Cargo.toml

@@ -169,9 +169,14 @@ fn get_commits_till_head_from_oid(
         commits.push_front(commit);
     }
 
-    debug!("Operating upon {} commits.", commits.len());
-
-    Ok(commits)
+    if commits.is_empty() {
+        let error_message = "No Git commits within the provided range.".to_string();
+        error!("{error_message}");
+        Err(git2::Error::from_str(&error_message))
+    } else {
+        debug!("Operating upon {} commits.", commits.len());
+        Ok(commits)
+    }
 }
 
 fn get_reference_oid(repository: &Repository, matching: &str) -> Result<Oid, git2::Error> {