Add input version-file (#486)

Closes: #411

src/version/requirements-file.ts

@@ -0,0 +1,43 @@
+import * as toml from "smol-toml";
+import fs from "node:fs";
+
+export function getUvVersionFromRequirementsFile(
+  filePath: string,
+): string | undefined {
+  const fileContent = fs.readFileSync(filePath, "utf-8");
+  if (filePath.endsWith(".txt")) {
+    return getUvVersionFromAllDependencies(fileContent.split("\n"));
+  }
+  const dependencies = parsePyprojectDependencies(fileContent);
+  return getUvVersionFromAllDependencies(dependencies);
+}
+function getUvVersionFromAllDependencies(
+  allDependencies: string[],
+): string | undefined {
+  return allDependencies
+    .find((dep: string) => dep.startsWith("uv"))
+    ?.match(/^uv([^A-Z0-9._-]+.*)$/)?.[1]
+    .trim();
+}
+
+interface Pyproject {
+  project?: {
+    dependencies?: string[];
+    "optional-dependencies"?: Record<string, string[]>;
+  };
+  "dependency-groups"?: Record<string, Array<string | object>>;
+}
+
+function parsePyprojectDependencies(pyprojectContent: string): string[] {
+  const pyproject: Pyproject = toml.parse(pyprojectContent);
+  const dependencies: string[] = pyproject?.project?.dependencies || [];
+  const optionalDependencies: string[] = Object.values(
+    pyproject?.project?.["optional-dependencies"] || {},
+  ).flat();
+  const devDependencies: string[] = Object.values(
+    pyproject?.["dependency-groups"] || {},
+  )
+    .flat()
+    .filter((item: string | object) => typeof item === "string");
+  return dependencies.concat(optionalDependencies, devDependencies);
+}