noJsonUnsafeValues (JSON)

Language JSON (and super languages)

Summary

Rule available since: v2.5.14
Diagnostic Category: lint/nursery/noJsonUnsafeValues
This rule doesn’t have a fix.
The default severity of this rule is warning.
Sources:
- Same as json/no-unsafe-values

How to configure

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{
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  "linter": {
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    "rules": {
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      "nursery": {
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        "noJsonUnsafeValues": "error"
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      }
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    }
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  }
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}

Description

Disallow unsafe JSON values that may cause interoperability issues.

JSON parsers in different languages can use different number and Unicode representations. A value accepted by one parser may lose information or fail in another.

The rule reports:

lone UTF-16 surrogates, which are incomplete halves of an encoded Unicode character;
numbers outside JavaScript’s finite range, such as 1e400;
tiny nonzero numbers, such as 1e-400, that become zero because of limited precision;
integers outside JavaScript’s safe range (-(2^53 - 1) through 2^53 - 1), which lose precision;
subnormal numbers, which are extremely small floating-point values that systems may handle differently.

These values can cause data loss or inconsistent behavior when JSON moves between systems.

Examples

Invalid

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{
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  "invalid1": 2e308
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}

code-block.json:2:15 lint/nursery/noJsonUnsafeValues ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ The number will evaluate to Infinity.
  
    1 │ {
  > 2 │   "invalid1": 2e308
      │               ^^^^^
    3 │ }
    4 │ 
  
  ℹ Certain values can cause interoperability issues between different parsers and environments. Replace this value with a safe alternative.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.

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{
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  "invalid2": -2e308
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}

code-block.json:2:15 lint/nursery/noJsonUnsafeValues ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ The number will evaluate to Infinity.
  
    1 │ {
  > 2 │   "invalid2": -2e308
      │               ^^^^^^
    3 │ }
    4 │ 
  
  ℹ Certain values can cause interoperability issues between different parsers and environments. Replace this value with a safe alternative.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.

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{
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  "invalid3": "\ud83d"
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}

code-block.json:2:15 lint/nursery/noJsonUnsafeValues ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Lone surrogate found.
  
    1 │ {
  > 2 │   "invalid3": "\ud83d"
      │               ^^^^^^^^
    3 │ }
    4 │ 
  
  ℹ Certain values can cause interoperability issues between different parsers and environments. Replace this value with a safe alternative.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.

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{
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  "invalid4": 1e-400
3
}

code-block.json:2:15 lint/nursery/noJsonUnsafeValues ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ The number will evaluate to zero.
  
    1 │ {
  > 2 │   "invalid4": 1e-400
      │               ^^^^^^
    3 │ }
    4 │ 
  
  ℹ Certain values can cause interoperability issues between different parsers and environments. Replace this value with a safe alternative.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.

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{
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  "invalid5": 9007199254740992
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}

code-block.json:2:15 lint/nursery/noJsonUnsafeValues ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ The integer is outside the safe integer range.
  
    1 │ {
  > 2 │   "invalid5": 9007199254740992
      │               ^^^^^^^^^^^^^^^^
    3 │ }
    4 │ 
  
  ℹ Certain values can cause interoperability issues between different parsers and environments. Replace this value with a safe alternative.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.

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{
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  "invalid6": 2.2250738585072009e-308
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}

code-block.json:2:15 lint/nursery/noJsonUnsafeValues ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ Unexpected subnormal number found, which may cause interoperability issues.
  
    1 │ {
  > 2 │   "invalid6": 2.2250738585072009e-308
      │               ^^^^^^^^^^^^^^^^^^^^^^^
    3 │ }
    4 │ 
  
  ℹ Certain values can cause interoperability issues between different parsers and environments. Replace this value with a safe alternative.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.

Valid

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[
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  123,
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  1234,
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  12345, // Regular numbers within safe range
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  "🔥", // Properly formed Unicode character (fire emoji)
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  "\ud83d\udd25", // Same character with proper surrogate pair
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  0.00000,
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  0e0000000,
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  0.00000e0000 // Zero represented in different valid ways
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]