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Issuer Plugin

The Issuer plugin generates problematic but technically valid values for edge case testing. Use it to stress-test your applications with unusual inputs.

Why Issuer?​

Real-world data contains edge cases that break assumptions:

  • Unicode characters that look like ASCII
  • Extremely long strings
  • SQL-like patterns in user input
  • Dates at system boundaries

The Issuer plugin helps you test these scenarios proactively.

Unicode Generators​

Zero-Width Characters​

schema Test {
  // String with invisible characters
  name: issuer.zeroWidth()
}
// Output: "hel​lo" (contains zero-width space)

Homoglyphs​

Characters that look like other characters:

schema Security {
  // Looks like "admin" but uses Cyrillic 'а'
  username: issuer.homoglyph("admin")
}
// Output: "аdmin" (first 'a' is Cyrillic)

Right-to-Left Text​

schema International {
  // Contains RTL override characters
  text: issuer.rtl()
}

Emoji​

schema Social {
  // Emoji that might break string handling
  reaction: issuer.emoji()
}

String Generators​

Empty String​

schema Edge {
  // Empty string (not null)
  name: issuer.empty()
}
// Output: ""

Long Strings​

schema Stress {
  // Very long string
  description: issuer.long(10000)
}
// Output: "aaaa..." (10000 characters)

SQL-Like Patterns​

schema Injection {
  // Strings that look like SQL injection
  input: issuer.sqlLike()
}
// Output: "'; DROP TABLE users; --"

HTML Special Characters​

schema XSS {
  // HTML/XSS-like strings
  content: issuer.htmlSpecial()
}
// Output: "<script>alert('xss')</script>"

Number Generators​

Boundary Values​

schema Numbers {
  maxInt: issuer.maxInt(),         // 2^53 - 1 (JS max safe integer)
  minInt: issuer.minInt(),         // -(2^53 - 1)
  tinyDecimal: issuer.tinyDecimal(), // Very small decimal
  negativeZero: issuer.negativeZero() // -0
}

Date Generators​

Edge Case Dates​

schema Dates {
  leapDay: issuer.leapDay(),    // Feb 29 on a leap year
  y2k: issuer.y2k(),            // 2000-01-01
  epoch: issuer.epoch(),        // 1970-01-01
  farFuture: issuer.farFuture() // Year 2100+
}

Format Generators​

Unusual Valid Formats​

schema Formats {
  // Valid but unusual email
  email: issuer.weirdEmail(),
  // Output: "user+tag@sub.domain.co.uk"

  // Valid but unusual URL
  url: issuer.weirdUrl(),
  // Output: "https://user:pass@sub.example.com:8080/path?q=1#hash"

  // UUID with edge patterns
  id: issuer.specialUuid()
  // Output: "00000000-0000-0000-0000-000000000000"
}

Complete Reference​

GeneratorDescriptionExample
issuer.zeroWidth()Zero-width characters"hel​lo"
issuer.homoglyph(s)Lookalike characters"аdmin"
issuer.rtl()Right-to-left text"‮hello"
issuer.emoji()Emoji characters"👨‍👩‍👧‍👦"
issuer.empty()Empty string""
issuer.long(n)Long string"aaa..."
issuer.sqlLike()SQL injection pattern"'; DROP TABLE--"
issuer.htmlSpecial()HTML/XSS pattern"<script>..."
issuer.maxInt()Max safe integer9007199254740991
issuer.minInt()Min safe integer-9007199254740991
issuer.tinyDecimal()Tiny decimal0.0000001
issuer.negativeZero()Negative zero-0
issuer.leapDay()Leap day date"2024-02-29"
issuer.y2k()Y2K date"2000-01-01"
issuer.epoch()Unix epoch"1970-01-01"
issuer.farFuture()Far future date"2100-01-01"
issuer.weirdEmail()Unusual email"a+b@c.d.e.f"
issuer.weirdUrl()Unusual URL"https://a:b@c:8080"
issuer.specialUuid()Edge case UUID"000...000"

Testing Strategy​

Use Issuer alongside normal data:

schema User {
  // 90% normal names, 10% edge cases
  name: 0.9: fullName() | 0.1: issuer.homoglyph("admin"),

  // 95% normal emails, 5% unusual
  email: 0.95: email() | 0.05: issuer.weirdEmail(),

  // Occasionally very long bios
  bio: 0.9: paragraph() | 0.1: issuer.long(5000)
}

Or use separate datasets:

dataset Normal {
  users: 100 of NormalUser
}

dataset EdgeCases {
  users: 20 of EdgeCaseUser
}

See Also​