prisma/prisma · error · Error

${path}: not valid JSON (${error instanceof Error ? error.me

Error message

${path}: not valid JSON (${error instanceof Error ? error.message : String(error)})

What it means

Thrown by the core 0.9→0.10 upgrade codemod (stamp-storage-types-kind) when `JSON.parse(raw)` fails on a `start-contract.json` or `end-contract.json` it discovered under a `migrations/` tree. Before stamping the `kind` discriminator the codemod must parse the snapshot; a structurally invalid file aborts the run. The parenthesised message is Node's native JSON parse error locating the bad token.

Source

Thrown at skills/upgrade/prisma-next-upgrade/upgrades/0.9-to-0.10/stamp-storage-types-kind.ts:319

  if (typeof value === 'object') {
    const entries = Object.entries(value as Record<string, unknown>);
    if (entries.length === 0) return '{}';
    const lines = entries.map(
      ([k, v]) => `${childIndent}${JSON.stringify(k)}: ${formatJson(v, indentLevel + 1)}`,
    );
    return `{\n${lines.join(',\n')}\n${indent}}`;
  }

  throw new Error(`Unsupported value: ${typeof value}`);
}

async function processFile(path: string): Promise<Result> {
  const raw = await readFile(path, 'utf-8');
  let parsed: unknown;
  try {
    parsed = JSON.parse(raw);
  } catch (error) {
    throw new Error(
      `${path}: not valid JSON (${error instanceof Error ? error.message : String(error)})`,
    );
  }
  const outcome = processContract(parsed, path);
  if (outcome.transformed === null) {
    return { path, status: 'already-clean', stamped: 0 };
  }
  const serialised = `${formatJson(outcome.transformed)}\n`;
  if (!dryRun) await writeFile(path, serialised, 'utf-8');
  return { path, status: dryRun ? 'needs-fix' : 'fixed', stamped: outcome.stamped };
}

const contracts = await findContractSnapshots(projectRoot);
if (contracts.length === 0) {
  console.error(`No start-contract.json / end-contract.json files found under ${projectRoot}.`);
  process.exit(1);
}

View on GitHub (pinned to 1243cdffbe)

Solutions

1. Open the file at the reported path and fix the syntax error at the position given in the parenthesised parse message.
2. If corrupted by a merge conflict, resolve the markers and re-run (the codemod is idempotent).
3. If the snapshot is disposable, regenerate it via the migration authoring tooling or restore from git, then re-run.
4. Run with `--check` first to enumerate all affected files before applying edits.

Example fix

// before — migrations/0001/start-contract.json
{
  "storage": {
    "types": {
      "Embedding1536": { "codecId": "pg/vector@1", ... },
    }  // <- trailing comma breaks JSON.parse
}

// after
{
  "storage": {
    "types": {
      "Embedding1536": { "codecId": "pg/vector@1", ... }
    }
  }
}

import { readFile } from 'node:fs/promises';

// Pre-validate every start-/end-contract.json before running the stamp upgrade.
async function assertContractSnapshotsAreValidJson(paths: string[]): Promise<void> {
  for (const path of paths) {
    const raw = await readFile(path, 'utf-8');
    try { JSON.parse(raw); }
    catch (error) {
      const msg = error instanceof Error ? error.message : String(error);
      throw new Error(`Refusing to run upgrade: ${path} is not valid JSON (${msg})`);
    }
  }
}

try {
  await runStampUpgrade(projectRoot);
} catch (error) {
  if (error instanceof Error && error.message.includes(': not valid JSON (')) {
    const offending = error.message.split(':')[0];
    console.error(`Stamp upgrade aborted: regenerate ${offending} via the CLI, then re-run.`);
    process.exit(1);
  }
  throw error;
}

When it happens

Trigger: Running the codemod against a `migrations/` tree containing a `start-contract.json`/`end-contract.json` that is not valid JSON: trailing comma, unquoted key, comment, BOM, truncation, or merge-conflict markers.

Common situations: Unresolved git merge/rebase conflict markers inside a committed contract snapshot; an interrupted CLI write left a truncated snapshot; a hand-edited snapshot with JSON5 syntax; a `.jsonc` accidentally committed as `.json`.

Related errors

• ${manifestPath}: not valid JSON (${error instanceof Error ?
• ${manifestPath}: manifest is not a JSON object
• ${path}: not valid JSON (${error instanceof Error ? error.me
• ${manifestPath}: manifest is missing a string `migrationHash
• ${filePath}: storage.types[${JSON.stringify(name)}] is neith

AI-assisted analysis of prisma/prisma@1243cdffbe (2026-08-01). Data as JSON: /data/errors/3f5fddd46c7cfa76.json. Report an issue: GitHub.