Review opaque sRGB pairs against a supplied target

{
  "label": "Supplied agency data"
}

{
  "code": "\nfunction fail(reason){throw new Error('input: '+reason);}\nfunction check(schema,value,where){\n if(value===null){if(schema.type==='null'||Array.isArray(schema.type)&&schema.type.includes('null'))return;fail(where+' wrong_type');}\n const type=Array.isArray(schema.type)?schema.type[0]:schema.type;\n if(type==='object'){\n  if(!value||typeof value!=='object'||Array.isArray(value))fail(where+' wrong_type');\n  for(const name of Object.keys(value))if(!Object.hasOwn(schema.properties,name))fail(where+' unknown_field');\n  for(const name of schema.required)if(!Object.hasOwn(value,name))fail(where+' missing_field');\n  for(const [name,shape]of Object.entries(schema.properties))check(shape,value[name],where+'.'+name);\n }else if(type==='array'){\n  if(!Array.isArray(value)||value.length>schema.maxItems)fail(where+' array_bound');\n  for(const item of value)check(schema.items,item,where+'[]');\n }else if(type==='string'){if(typeof value!=='string'||value.length>schema.maxLength)fail(where+' string_bound');}\n else if(type==='integer'){if(!Number.isSafeInteger(value)||value<schema.minimum||value>schema.maximum)fail(where+' integer_bound');}\n else if(type==='boolean'){if(typeof value!=='boolean')fail(where+' wrong_type');}\n else fail(where+' unsupported_type');\n}\nfunction id(value){if(typeof value!=='string'||!value||value.trim()!==value)fail('noncanonical_identity');return value;}\nfunction unique(values,reason){if(new Set(values).size!==values.length)fail(reason);}\nfunction safeAdd(a,b){if(a>Number.MAX_SAFE_INTEGER-b)fail('unsafe_sum');return a+b;}\nfunction day(value){if(!/^\\d{4}-\\d{2}-\\d{2}$/.test(value))fail('invalid_calendar_day');const ms=Date.parse(value+'T00:00:00Z');if(!Number.isFinite(ms)||new Date(ms).toISOString().slice(0,10)!==value)fail('invalid_calendar_day');return ms;}\nfunction refKey(ref){id(ref.assetId);if(ref.version<1)fail('positive_version_required');return JSON.stringify([ref.assetId,ref.version]);}\nfunction refValue(key){const pair=JSON.parse(key);return {assetId:pair[0],version:pair[1]};}\nfunction sortedRefs(keys){return [...keys].sort().map(refValue);}\n\nfunction lexIds(a,b){for(let i=0;i<Math.min(a.length,b.length);i++){if(a[i]<b[i])return -1;if(a[i]>b[i])return 1;}return a.length-b.length;}\nfunction maxSubset(rows,idField,feasible){let best=-1,ids=[],ties=0;for(let mask=0;mask<2**rows.length;mask++){const chosen=rows.filter((_,i)=>mask&(1<<i));if(!feasible(chosen))continue;const value=chosen.reduce((n,r)=>n+r.valuePoints,0),current=chosen.map(r=>r[idField]).sort();if(value>best){best=value;ids=current;ties=1;}else if(value===best){ties++;if(lexIds(current,ids)<0)ids=current;}}return {ids,value:best,ties};}\nfunction rat(n,d){if(d===0n)fail('zero_denominator');if(d<0n){n=-n;d=-d;}let a=n<0n?-n:n,b=d;while(b){const next=a%b;a=b;b=next;}return [n/a,d/a];}\nfunction ratAdd(a,b){return rat(a[0]*b[1]+b[0]*a[1],a[1]*b[1]);}\nfunction ratSub(a,b){return rat(a[0]*b[1]-b[0]*a[1],a[1]*b[1]);}\nfunction ratMul(a,b){return rat(a[0]*b[0],a[1]*b[1]);}\nfunction ratText(a){return a[0].toString()+'/'+a[1].toString();}\n\n\ncheck({\"type\":\"object\",\"properties\":{\"scopeId\":{\"type\":\"string\",\"maxLength\":128},\"pairs\":{\"type\":\"array\",\"items\":{\"type\":\"object\",\"properties\":{\"pairId\":{\"type\":\"string\",\"maxLength\":128},\"foreground\":{\"type\":\"string\",\"maxLength\":7},\"background\":{\"type\":\"string\",\"maxLength\":7},\"targetRatioBps\":{\"type\":\"integer\",\"minimum\":10000,\"maximum\":210000}},\"required\":[\"pairId\",\"foreground\",\"background\",\"targetRatioBps\"],\"additionalProperties\":false},\"maxItems\":30}},\"required\":[\"scopeId\",\"pairs\"],\"additionalProperties\":false},context.input,\"input\");\nconst result=(function contrast(x){\n id(x.scopeId);unique(x.pairs.map(p=>id(p.pairId)),'duplicate_pair_id');\n const luminance=hex=>{if(!/^#[0-9a-fA-F]{6}$/.test(hex))fail('invalid_opaque_hex');const c=[1,3,5].map(at=>parseInt(hex.slice(at,at+2),16)/255).map(v=>v<=0.04045?v/12.92:((v+0.055)/1.055)**2.4);return c[0]*0.2126+c[1]*0.7152+c[2]*0.0722;};\n return {rows:x.pairs.map(p=>{const a=luminance(p.foreground),b=luminance(p.background),ratio=(Math.max(a,b)+0.05)/(Math.min(a,b)+0.05);return {pairId:p.pairId,ratioBpsRounded:Math.round(ratio*10000),meetsSuppliedTarget:ratio>=p.targetRatioBps/10000};}).sort((a,b)=>a.pairId<b.pairId?-1:a.pairId>b.pairId?1:0)};\n})(context.input);\ncheck({\"type\":\"object\",\"properties\":{\"rows\":{\"type\":\"array\",\"items\":{\"type\":\"object\",\"properties\":{\"pairId\":{\"type\":\"string\",\"maxLength\":128},\"ratioBpsRounded\":{\"type\":\"integer\",\"minimum\":10000,\"maximum\":210000},\"meetsSuppliedTarget\":{\"type\":\"boolean\"}},\"required\":[\"pairId\",\"ratioBpsRounded\",\"meetsSuppliedTarget\"],\"additionalProperties\":false},\"maxItems\":30}},\"required\":[\"rows\"],\"additionalProperties\":false},result,\"output\");\nreturn result;",
  "label": "Review opaque sRGB pairs against a supplied target",
  "memoryLimit": 16,
  "outputVar": "result",
  "timeout": 1000
}