search in parent dir (#306)

Fixes:  #164

---------

Co-authored-by: Clawdbot <clawdbot@users.noreply.github.com>

src/utils/pyproject-finder.ts

@@ -0,0 +1,79 @@
+import * as fs from "node:fs";
+import * as path from "node:path";
+import * as core from "@actions/core";
+
+/**
+ * Search for a pyproject.toml file starting from the given directory
+ * and traversing upwards through parent directories until reaching
+ * the GitHub workspace root.
+ *
+ * @param startDir The directory to start the search from (e.g., the src input)
+ * @param workspaceRoot The GitHub workspace directory (GITHUB_WORKSPACE)
+ * @returns The path to the found pyproject.toml, or undefined if not found
+ */
+export function findPyprojectToml(
+  startDir: string,
+  workspaceRoot: string,
+): string | undefined {
+  let currentDir = path.resolve(startDir);
+  const resolvedWorkspaceRoot = path.resolve(workspaceRoot);
+
+  while (true) {
+    const pyprojectPath = path.join(currentDir, "pyproject.toml");
+    core.debug(`Checking for ${pyprojectPath}`);
+
+    if (fs.existsSync(pyprojectPath)) {
+      core.info(`Found pyproject.toml at ${pyprojectPath}`);
+      return pyprojectPath;
+    }
+
+    // Check if we've reached the workspace root
+    if (currentDir === resolvedWorkspaceRoot) {
+      // If we're at workspace root and didn't find it, stop searching
+      break;
+    }
+
+    // Move up to parent directory
+    const parentDir = path.dirname(currentDir);
+
+    // If parent is the same as current, we've reached the filesystem root
+    if (parentDir === currentDir) {
+      break;
+    }
+
+    currentDir = parentDir;
+
+    // If we've gone past the workspace root, stop searching
+    if (isPathWithinWorkspace(currentDir, resolvedWorkspaceRoot) === false) {
+      break;
+    }
+  }
+
+  return undefined;
+}
+
+/**
+ * Check if a given path is within or equal to the workspace root.
+ *
+ * @param checkPath The path to check
+ * @param workspaceRoot The workspace root directory
+ * @returns true if within or equal to workspace, false if outside, undefined if can't determine
+ */
+function isPathWithinWorkspace(
+  checkPath: string,
+  workspaceRoot: string,
+): boolean | undefined {
+  try {
+    const checkPathResolved = path.resolve(checkPath);
+    const workspaceRootResolved = path.resolve(workspaceRoot);
+
+    // Check if checkPath starts with workspaceRoot (case-insensitive on Windows)
+    const relativePath = path.relative(
+      workspaceRootResolved,
+      checkPathResolved,
+    );
+    return !relativePath.startsWith("..") && !path.isAbsolute(relativePath);
+  } catch {
+    return undefined;
+  }
+}