FindProxyForURL Beta

PAC-E003 · duplicate-findproxyforurl

FindProxyForURL declared more than once

high · Errors and robustness

Two or more function declarations named FindProxyForURL. JavaScript keeps the last one; the others are dead code that still looks authoritative to a reader.

Why it matters

Function declarations are hoisted and later declarations overwrite earlier ones. When a PAC contains two FindProxyForURL bodies (usually after merging two files or keeping an old version “for reference”), the engine runs only the last one. Whoever edits the first body sees no effect and may conclude the PAC is broken or cached.

How to fix

Keep exactly one FindProxyForURL; move alternative versions out of the file or into version control.

Examples

Bad

function FindProxyForURL(url, host) {
  return "PROXY old-proxy.corp.example:8080";
}
function FindProxyForURL(url, host) {
  return "PROXY proxy.corp.example:8080";
}
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Good

function FindProxyForURL(url, host) {
  return "PROXY proxy.corp.example:8080";
}
Open good example in checker

Related rules

References