```ts
export function parseSemver(version: string): { major: number; minor: number; patch: number; prerelease: string | null; build: string | null } {
  if (typeof version !== 'string') {
    throw new Error(`Invalid version input: ${version}`);
  }

  const semverRegex = /^(\d+)\.(\d+)\.(\d+)(?:-([^+]+))?(?:\+(.+))?$/;
  const match = version.match(semverRegex);

  if (!match) {
    throw new Error(`Invalid version format: ${version}`);
  }

  const [, majorStr, minorStr, patchStr, prerelease, build] = match;

  // Validate that numbers don't have leading zeros (except "0" itself)
  if (majorStr.length > 1 && majorStr[0] === '0') {
    throw new Error(`Invalid version format: ${version}`);
  }
  if (minorStr.length > 1 && minorStr[0] === '0') {
    throw new Error(`Invalid version format: ${version}`);
  }
  if (patchStr.length > 1 && patchStr[0] === '0') {
    throw new Error(`Invalid version format: ${version}`);
  }

  return {
    major: parseInt(majorStr, 10),
    minor: parseInt(minorStr, 10),
    patch: parseInt(patchStr, 10),
    prerelease: prerelease || null,
    build: build || null
  };
}
```