Description
Audit declaration property duplicates with ordinary ASCII property folding and case-sensitive custom-property names; not a cascade engine.
CSS combines token syntax, property-specific value rules and layout/cascade processing. These are separate layers: splitting a declaration does not establish that its value is valid, and arithmetic on resolved lengths does not perform browser layout. Each tool here handles an explicit numeric representation or a stated lexical subset.
Audit declaration property duplicates with ordinary ASCII property folding and case-sensitive custom-property names; not a cascade engine.
When to use this tool
Use this tool to audit declaration property duplicates with ordinary ASCII property folding and case-sensitive custom-property names; not a cascade engine.
How to use the tool and how it works
- Enter text using the input definitions below.
- Run the operation. Resolve malformed-input errors before interpreting the result.
- Read result.duplicates. Interpret signs, units, ordering and null values using the rules below.
Parse the declaration list, then group repeated normalized property names with all original declaration indexes in first-seen order. Ordinary names are lowercase; custom-property names retain case.1, 2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| text | CSS-subset text to parse under the operation’s stated grammar. | Text, at most 8,192 UTF-16 code units; the stated grammar and narrower limits also apply. |
| Output field | Interpretation |
|---|---|
| result | Object containing the fields below. |
| result.duplicates | Repeated normalized property groups with declaration indexes. |
{
"input": {
"text": "Color:red;color:blue;--X:1;--x:2"
},
"output": {
"result": {
"duplicates": [
{
"key": "color",
"indexes": [
0,
1
]
}
]
}
}
}Limitations and assumptions
- A duplicate occurrence is not automatically an error or a cascade winner; importance and other cascade rules need separate evaluation.
- Lengths and times must already be resolved to consistent numeric units. Lexical helpers intentionally support smaller grammars than a full browser CSS parser; malformed supported-subset input causes an error.
- Every declared top-level input is required and unknown fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
- Numeric outputs must be finite and within the absolute safe-integer magnitude; exact larger integers use decimal text. Source positions are zero-based UTF-16 offsets and span ends are exclusive unless a different convention is explicitly stated.
Alternative or Complementary methods
Use a full CSS parser or browser style/layout APIs when escape handling, error recovery, computed styles or the full cascade matter. These tools expose focused transformations and audits of supplied data.
References
Similar or alternative tools
- CSS Custom Property Name Token Audit
Audit a deliberately restricted ASCII custom-property token grammar -- followed by letters/digits/underscore/dash; not full CSS identifier validation.
- CSS Custom Property Reference Inventory
Inventory unescaped ASCII var() reference names including nested fallbacks, ignoring quoted strings; existing variable-parser extracts declarations instead. Comment-free balanced CSS subset.