alibaba/arthas · error · Error

Configuration should be an object

Error message

Configuration should be an object

What it means

configuration setter throws when typeof configuration !== 'object'. null and arrays pass (typeof both yield 'object'); primitives are rejected. The object is later consulted key-by-key by getConfigItemOrDefault, so a primitive has no usable keys.

Source

Thrown at labs/arthas-jfr-frontend/src/components/FlameGraph/flame-graph-class.js:625

    }
    if (typeof dataSource.format !== 'string') {
      throw new Error('Illegal dataSource format type, must be string');
    }
    let format = dataSource.format.toLowerCase();
    if ('line' !== format && 'tree' !== format) {
      throw new Error("Illegal dataSource format, must be 'line' or 'tree'");
    }
    this.$dataSource = dataSource;
    this.render(true, true);
  }

  get dataSource() {
    return this.$dataSource;
  }

  set configuration(configuration) {
    if (typeof configuration !== 'object') {
      throw new Error('Configuration should be an object');
    }
    this.$configuration = configuration;
  }

  get configuration() {
    return this.$configuration;
  }

  getConfigItemOrDefault(name, def) {
    if (this.$configuration && this.$configuration[name]) {
      return this.$configuration[name];
    }
    return def;
  }

  _(name, def) {
    return this.getConfigItemOrDefault(name, def);
  }

View on GitHub (pinned to 21cf2e9ba5)

Solutions

1. Pass a plain object such as { theme: 'dark' }.
2. Pass null or {} when you have no config.
3. Parse serialized configs with JSON.parse first.

Example fix

// before
el.configuration = cfgString; // throws

// after
el.configuration = JSON.parse(cfgString);

if (configuration != null && typeof configuration !== 'object') throw new TypeError('configuration must be object');
el.configuration = configuration;

function isConfigObject(c) { return c == null || (typeof c === 'object' && !Array.isArray(c)); }

When it happens

Trigger: Assigning element.configuration = 'dark'; assigning a number/boolean; assigning a JSON string that was not parsed.

Common situations: Passing a single scalar where an options bag is expected; forgetting JSON.parse on a serialized config.

Related errors

• Illegal dataSource format type, must be string
• Configuration should be an object
• Illegal dataSource format type, must be string
• Unsupported dataSource format ${format}
• Should specify the format of dataSource: 'line' or 'tree'

AI-assisted analysis of alibaba/arthas@21cf2e9ba5 (2026-08-14). Data as JSON: /api/errors/3c57a1dabeef7454. Report an issue: GitHub.