feat: Add --scan-dryrun-results flag for Maven test runner

launchable/test_runners/maven.py

@@ -1,6 +1,7 @@
 import glob
 import os
 import re
+import xml.etree.ElementTree as ET
 from typing import Dict, List, Optional, Tuple
 
 import click
@@ -46,6 +47,33 @@ def is_file(f: str) -> bool:
     return False
 
 
+def parse_surefire_reports() -> List[Dict[str, str]]:
+    """Parse Maven Surefire XML reports from target/surefire-reports/."""
+    test_paths = []
+    report_pattern = '**/target/surefire-reports/TEST-*.xml'
+    report_files = glob.glob(report_pattern, recursive=True)
+
+    if not report_files:
+        return []
+
+    click.echo(f"Found {len(report_files)} surefire report(s)", err=True)
+
+    for report_file in report_files:
+        try:
+            tree = ET.parse(report_file)
+            root = tree.getroot()
+            classname = root.get('name')
+
+            if classname:
+                test_paths.append({"type": "class", "name": classname})
+
+        except ET.ParseError as e:
+            click.secho(f"Warning: Could not parse {report_file}: {e}", fg='yellow', err=True)
+
+    click.echo(f"Total tests discovered: {len(test_paths)}", err=True)
+    return test_paths
+
+
 @click.option(
     '--test-compile-created-file',
     'test_compile_created_file',
@@ -61,6 +89,12 @@ def is_file(f: str) -> bool:
     is_flag=True,
     help="Scan testCompile/default-testCompile/createdFiles.lst for *.lst files generated by `mvn compile` and use them as test inputs.",  # noqa: E501
 )
+@click.option(
+    '--scan-dryrun-results',
+    'is_scan_dryrun_results',
+    is_flag=True,
+    help="Scan surefire reports generated by mvn test -DdryRun=true",
+)
 @click.option(
     '--exclude',
     'exclude_rules',
@@ -70,7 +104,14 @@ def is_file(f: str) -> bool:
 )
 @click.argument('source_roots', required=False, nargs=-1)
 @launchable.subset
-def subset(client, source_roots, test_compile_created_file, is_scan_test_compile_lst, exclude_rules: Tuple[str, ...]):
+def subset(
+    client,
+    source_roots,
+    test_compile_created_file,
+    is_scan_test_compile_lst,
+    is_scan_dryrun_results,
+    exclude_rules: Tuple[str, ...]
+):
 
     # Compile exclude rules
     compiled_exclude_rules = []
@@ -100,23 +141,45 @@ def file2test(f: str) -> Optional[List]:
         else:
             return None
 
-    files_to_read = list(test_compile_created_file)
-    if is_scan_test_compile_lst:
-        if len(test_compile_created_file) > 0:
-            click.echo(click.style(
-                "Warning: --test-compile-created-file is overridden by --scan-test-compile-lst", fg="yellow"),
-                err=True)
+    if is_scan_dryrun_results:
+        click.echo("Scanning Maven dry-run results...", err=True)
+        tests = parse_surefire_reports()
+
+        if not tests:
+            click.secho(
+                "Warning: No surefire reports found. Did you run 'mvn test -DdryRun=true'?",
+                fg='yellow',
+                err=True
+            )
+            click.secho(
+                "Please run: mvn test -DdryRun=true",
+                fg='cyan',
+                err=True
+            )
+            return
+
+        # Add tests to client (each test path must be a list)
+        for test in tests:
+            client.test_paths.append([test])
 
-        pattern = os.path.join('**', 'createdFiles.lst')
-        files_to_read = glob.glob(pattern, recursive=True)
+    elif is_scan_test_compile_lst or test_compile_created_file:
+        if is_scan_test_compile_lst:
+            if len(test_compile_created_file) > 0:
+                click.echo(click.style(
+                    "Warning: --test-compile-created-file is overridden by --scan-test-compile-lst", fg="yellow"),
+                    err=True)
 
-        if not files_to_read:
-            click.echo(click.style(
-                "Warning: No .lst files. Please run after executing `mvn test-compile`", fg="yellow"),
-                err=True)
-            return
+            pattern = os.path.join('**', 'createdFiles.lst')
+            files_to_read = glob.glob(pattern, recursive=True)
+
+            if not files_to_read:
+                click.echo(click.style(
+                    "Warning: No .lst files. Please run after executing `mvn test-compile`", fg="yellow"),
+                    err=True)
+                return
+        elif test_compile_created_file:
+            files_to_read = list(test_compile_created_file)
 
-    if files_to_read:
         for file in files_to_read:
             with open(file, 'r') as f:
                 lines = f.readlines()
@@ -132,6 +195,7 @@ def file2test(f: str) -> Optional[List]:
                     path = file2test(l)
                     if path:
                         client.test_paths.append(path)
+
     else:
         for root in source_roots:
             client.scan(root, '**/*', file2test)

tests/data/maven/README.md

@@ -0,0 +1,69 @@
+# Maven Test Data
+
+This directory contains test fixtures for the Maven test runner, including sample Maven Surefire reports used to test the `--scan-dryrun-results` feature.
+
+## Directory Structure
+
+- `dryrun-test/` - Test data for the `--scan-dryrun-results` feature
+  - `target/surefire-reports/` - Sample Maven Surefire reports (XML and TXT formats)
+- `reports/` - Sample test result XML files for various test scenarios
+
+## How to Test Manually with Your Own Project
+
+To manually test the `--scan-dryrun-results` feature with your own Maven project:
+
+```bash
+# 1. Navigate to your Maven project
+cd /path/to/your/maven-project
+
+# 2. Run Maven dry-run to generate reports
+mvn test -DdryRun=true
+
+# 3. Verify reports were created
+ls -la target/surefire-reports/TEST-*.xml
+
+# 4. Set up environment (if not already set)
+export LAUNCHABLE_TOKEN='v1:your-org/your-workspace:your-actual-token'
+
+# 5. Record build
+launchable record build --name 'test-build-name'
+
+# 6. Create a session
+launchable record session --build 'test-build-name'
+# Copy the session ID from output, e.g., builds/test-build-name/test_sessions/123
+
+# 7. Run subset with --scan-dryrun-results
+launchable subset maven \
+  --scan-dryrun-results \
+  --session builds/test-build-name/test_sessions/123 \
+  --target 10%
+```
+
+## Creating Test Files for `--scan-dryrun-results`
+
+The test files in `dryrun-test/target/surefire-reports/` are fixtures that simulate Maven Surefire reports generated by running tests with Maven's dry-run mode.
+
+### How to Create/Update These Files
+
+To create or update test fixture files, run Maven tests from within the `dryrun-test` directory:
+
+```bash
+cd tests/data/maven/dryrun-test
+
+# Run Maven dry-run to generate Surefire reports
+mvn test -DdryRun=true
+
+# The reports will be automatically generated in target/surefire-reports/
+# - XML files: TEST-*.xml (detailed test execution results)
+# - TXT files: *.txt (summary information for each test class)
+```
+
+The generated reports in `target/surefire-reports/` are used directly as test fixtures.
+
+### Purpose
+
+These fixtures are used to test:
+- Parsing of Maven Surefire XML reports
+- The `--scan-dryrun-results` flag functionality
+- Integration with Launchable's subset API
+- Handling of filtered/excluded tests