Edit Doctor — Development skill for Claude Code

edit-doctor

When Claude Code's Edit tool can't find the text it was asked to replace, it fails with `String to replace not found in file.` and nothing else. The usual causes are invisible: the file indents with tabs and Claude typed spaces, a line ends in spaces Claude didn't copy, a no-break space or zero-width character sits where Claude typed a plain space, or the file changed since Claude read it. Claude usually reads the whole file again and guesses. `Found 2 matches of the string to replace` and `File does not exist` are just as bare.

edit-doctor reads the file the moment an Edit fails and tells Claude, before its next step, exactly what differs and what to use instead:

• Text not found. It finds old_string in the file again with whitespace, invisible characters and typography set aside, then lists every difference by line and column: a tab where Claude has spaces, trailing spaces, a no-break space, a zero-width character, an en dash where Claude typed a hyphen. It quotes the exact text from the file to copy. When the text really changed, it shows the closest lines and what differs in them.
• Several matches. It lists where each one is and which neighbouring line makes each unique, so Claude can widen old_string instead of guessing.
• File does not exist. For Edit and Read, it suggests the files Claude probably meant: the same name in another folder, the same name with another extension or capitalisation, or a name a typo away.
• replace_all changed more than you think. An Edit with replace_all reports only "All occurrences were successfully replaced". edit-doctor tells Claude how many places changed and on which lines, and points out any that were inside a longer word, such as foo inside foobar, so a too-broad replacement gets caught right away.

Here is what Claude saw, in a real session, after an Edit that indented two lines of a Go file with spaces:

edit-doctor: the Edit to live.go failed because old_string is not in the fi