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📄 applyDefault.ts

📊 Analysis Summary

Metric	Count
🔧 Functions	1
📦 Imports	2
📊 Variables & Constants	2
📑 Type Aliases	1

📚 Table of Contents

• Imports
• Variables & Constants
• Functions
• Type Aliases

🛠️ File Location:

📂 packages/utils/src/eslint-utils/applyDefault.ts

📦 Imports

Name	Source
deepMerge	./deepMerge
isObjectNotArray	./deepMerge

---

Variables & Constants

Name	Type	Kind	Value	Exported
options	AsMutable<Default>	const	structuredClone(defaultOptions) as AsMutable<Default>	✗
userOpt	unknown	const	userOptions[i]	✗

---

Functions

applyDefault(defaultOptions: Readonly<Default>, userOptions: Readonly<User> | null): Default

Code

export function applyDefault<
  User extends readonly unknown[],
  Default extends User,
>(
  defaultOptions: Readonly<Default>,
  userOptions: Readonly<User> | null,
): Default {
  // clone defaults
  const options = structuredClone(defaultOptions) as AsMutable<Default>;

  if (userOptions == null) {
    return options;
  }

  // For avoiding the type error
  //   `This expression is not callable. Type 'unknown' has no call signatures.ts(2349)`
  (options as unknown[]).forEach((opt: unknown, i: number) => {
    // eslint-disable-next-line @typescript-eslint/internal/eqeq-nullish
    if (userOptions[i] !== undefined) {
      const userOpt = userOptions[i];

      if (isObjectNotArray(userOpt) && isObjectNotArray(opt)) {
        options[i] = deepMerge(opt, userOpt);
      } else {
        options[i] = userOpt;
      }
    }
  });

  return options;
}

• JSDoc:

  /**
   * Pure function - doesn't mutate either parameter!
   * Uses the default options and overrides with the options provided by the user
   * @param defaultOptions the defaults
   * @param userOptions the user opts
   * @returns the options with defaults
   */
  

• Parameters:

• defaultOptions: Readonly<Default>
• userOptions: Readonly<User> | null
• Return Type: Default
• Calls:
• structuredClone
• (options as unknown[]).forEach
• isObjectNotArray (from ./deepMerge)
• deepMerge (from ./deepMerge)
• Internal Comments:

  // clone defaults (x2)
  // For avoiding the type error (x4)
  //   `This expression is not callable. Type 'unknown' has no call signatures.ts(2349)` (x4)
  // eslint-disable-next-line @typescript-eslint/internal/eqeq-nullish
  

---

Type Aliases

AsMutable<T extends readonly unknown[] extends readonly unknown[]>

type AsMutable<T extends readonly unknown[] extends readonly unknown[]> = {
  -readonly [Key in keyof T]: T[Key];
};

---