What causes "Could not read '${path}'." in cypress-io/cypress?

Verify the file named in the error message actually exists at the workspace root (e.g. `ls package.json angular.json tsconfig.json`).

cypress-io/cypress · error · Error

Could not read '${path}'.

Error message

Could not read '${path}'.

What it means

Thrown by the JSONFile constructor in @cypress/schematic when the Angular DevKit Tree host returns a falsy buffer for the requested path. The schematic relies on host.read() to load JSON files (package.json, angular.json, tsconfig.json) it must mutate; a null/undefined buffer means the file does not exist at that path in the virtual filesystem the schematic operates on. The message interpolates the constructor's `path` argument so you can see which file was missing.

Source

Thrown at npm/cypress-schematic/src/schematics/utils/jsonFile.ts:36

  parseTree,
  printParseErrorCode,
} from 'jsonc-parser'

export type InsertionIndex = (properties: string[]) => number

export type JSONPath = (string | number)[]

/** @internal */
export class JSONFile {
  content: string

  constructor (private readonly host: Tree, private readonly path: string) {
    const buffer = this.host.read(this.path)

    if (buffer) {
      this.content = buffer.toString()
    } else {
      throw new Error(`Could not read '${path}'.`)
    }
  }

  private _jsonAst: Node | undefined
  private get JsonAst (): Node | undefined {
    if (this._jsonAst) {
      return this._jsonAst
    }

    const errors: ParseError[] = []

    this._jsonAst = parseTree(this.content, errors, { allowTrailingComma: true })
    if (errors.length) {
      const { error, offset } = errors[0]

      throw new Error(
         `Failed to parse "${this.path}" as JSON AST Object. ${printParseErrorCode(
           error,

View on GitHub (pinned to 0d85fdc912)

Solutions

Verify the file named in the error message actually exists at the workspace root (e.g. `ls package.json angular.json tsconfig.json`).
Ensure you run `ng add @cypress/schematic` from the Angular workspace root, not a subdirectory or the parent folder.
If the file legitimately does not exist (e.g. a minimal project), create a minimal valid JSON file at the path before re-running the schematic.
Update @cypress/schematic to the latest version compatible with your Angular CLI major version.

Example fix

// before: run from /packages/frontend while angular.json lives at repo root
ng add @cypress/schematic
// after: run from the workspace root that contains angular.json
cd /repo-root && ng add @cypress/schematic

Defensive patterns

Strategy: validation

Validate before calling

// before constructing JSONFile in a schematic
import { existsSync } from './exists';
function readJsonSafe(host: Tree, p: string) {
  if (!host.exists(p)) { // DevKit Tree has exists()
    throw new Error(`Refusing to open missing file: ${p}`)
  }
  return new JSONFile(host, p)
}

Type guard

const isReadablePath = (host: Tree, p: string): boolean => typeof p === 'string' && p.length > 0 && !!host.exists && host.exists(p)

Try / catch

try {
  const f = new JSONFile(host, path)
  // ... mutate f
} catch (e) {
  if (e instanceof Error && e.message.startsWith("Could not read")) {
    // graceful: skip this file, log, or prompt user
  } else throw e
}

Prevention

Validate file existence with host.exists(path) before constructing JSONFile.
Run schematics from the workspace root that contains angular.json/package.json.
Pre-check required files in the schematic's factory before passing them to JSONFile.

When it happens

Trigger: Instantiating `new JSONFile(host, path)` where `host.read(path)` returns null or undefined. Happens during `ng add @cypress/schematic` when a JSON file the schematic expects (e.g. tsconfig.json or package.json) is absent, misnamed, outside the workspace root, or when the schematic was pointed at a path the Tree cannot resolve.

Common situations: Running the schematic in a non-standard Angular workspace (e.g. an Nx monorepo, a workspace with package.json at a different level), running against a project that never ran `npm init`, or after a partial workspace where the schematic's target file was deleted/moved. Also seen when the schematic version expects a file the user's Angular version does not generate.

Related errors

AI-assisted analysis of cypress-io/cypress@0d85fdc912 (2026-08-12). Data as JSON: /api/errors/5c46a58b81891ef3. Report an issue: GitHub.