karatelabs/karate · error · RuntimeException

Invalid get expression, missing ]:

Error message

Invalid get expression, missing ]: 

What it means

The `get` keyword supports the `get[N] var.path` syntax for list indexing. The executor scans for the closing ']' to split the index from the remainder path; if the expression starts with 'get[' but contains no ']', the bracket is unbalanced and parsing cannot proceed, so this error is thrown with the raw expression.

Solutions

1. Add the closing bracket: `get[0] myList`
2. Prefer the bracket-on-variable form if clearer: `myList[0]` inside def/eval
3. Check the step text was not truncated by templating or line-wrapping
4. Verify no nested brackets are confusing the parser

Example fix

// before
* def first = get[0 items
// after
* def first = get[0] items

* if (!getExpr.startsWith('get[') || getExpr.indexOf(']') < 0) karate.fail('malformed get expression')

When it happens

Trigger: `* def x = get[0 foo` (missing closing bracket); nested/broken expressions where the bracket was consumed or mistyped (e.g. `get(0] foo`); truncated text from templating.

Common situations: Hand-editing get expressions and dropping the bracket; generating steps programmatically with malformed templates; confusing `get[0] list` with `get list[0]` syntax and mixing forms.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• configure requires '=' assignment:
• def requires '=' assignment
• fromString JSON parse failed
• fromString XML parse failed
• invalid destructuring: rest element cannot have an…

AI-assisted analysis of karatelabs/karate@a22eb90246 (2026-09-12). Data as JSON: /api/errors/1f69ed2b5215f4a3. Report an issue: GitHub.

Appendix: source

Thrown at karate-core/src/main/java/io/karatelabs/core/StepExecutor.java:3153

    private Object evalCallOnceExpression(String callExpr) {
        String tempVar = "__callOnceResult__" + System.nanoTime();
        executeCallOnceWithResult(callExpr, tempVar);
        return runtime.getVariable(tempVar);
    }

    /**
     * Evaluates get[N] varname path or get varname path syntax.
     * Examples: get[0] foo[*].name, get foo $..bar, get xml //xpath
     */
    private Object evalGetExpression(String expr) {
        int index = -1;
        String remainder;

        if (expr.startsWith("get[")) {
            // get[N] syntax
            int closeBracket = expr.indexOf(']');
            if (closeBracket < 0) {
                throw new RuntimeException("Invalid get expression, missing ]: " + expr);
            }
            index = Integer.parseInt(expr.substring(4, closeBracket));
            remainder = expr.substring(closeBracket + 1).trim();
        } else {
            // get varname path
            remainder = expr.substring(4).trim();
        }

        // Parse varname and path - could be "varname path" or "varname[...]"
        String varName;
        String path;

        // Check if path starts with $ (explicit jsonpath)
        if (remainder.startsWith("$")) {
            // get $..path or get[0] $[*].foo - operates on 'response'
            varName = "response";
            path = remainder;
        } else {

View on GitHub (pinned to a22eb90246)