Text Processingflags: g

GraphQL Operation Header

Match GraphQL operation headers — `query`, `mutation`, or `subscription` — capturing the operation name.

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("(query|mutation|subscription)\\s+(\\w+)?\\s*(?:\\([^)]*\\))?\\s*\\{", "g");
const input = "query GetUser($id: ID!) { user(id: $id) { name } }";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).

Python (re) code

pyPython

import re

pattern = re.compile(r"(query|mutation|subscription)\s+(\w+)?\s*(?:\([^)]*\))?\s*\{")
input_text = "query GetUser($id: ID!) { user(id: $id) { name } }"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`(query|mutation|subscription)\s+(\w+)?\s*(?:\([^)]*\))?\s*\{`)
	input := `query GetUser($id: ID!) { user(id: $id) { name } }`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.

Pattern

regexengine-agnostic

(query|mutation|subscription)\s+(\w+)?\s*(?:\([^)]*\))?\s*\{   (flags: g)

Raw source: (query|mutation|subscription)\s+(\w+)?\s*(?:$[^)]*$)?\s*\{

How it works

(query|mutation|subscription) captures the operation type. \s+(\w+)? optionally captures the operation name (anonymous operations omit it). (?:$[^)]*$)? optionally matches a variables declaration `($var: Type)`. The trailing `\s*\{` matches the opening brace of the selection set.