When reporting an error to the user, add information about the offending
object/value (possibly truncated).
The goal is to give a user some context regarding which input object
caused the runtime error.
Examples:
$ echo '"hello"' | ./jq '-.'
jq: error: string ("hello") cannot be negated
$ echo '"very-long-string"' | ./jq '-.'
jq: error: string ("very-long-...) cannot be negated
$ echo '["1",2]' | ./jq '.|join(",")'
jq: error: string (",") and number (2) cannot be added
$ echo '["1","2",{"a":{"b":{"c":33}}}]' | ./jq '.|join(",")'
jq: error: string (",") and object ({"a":{"b":{...) cannot be added
$ echo '{"a":{"b":{"c":33}}}' | ./jq '.a | @tsv'
jq: error: object ({"b":{"c":33}}) cannot be tsv-formatted, only array
(Fix #754)
With this patch, jq run-time errors printed to stderr will contain the
filename and line of the offending input.
But note that the JSON text parser does (yet) print the input filename
on parse error. A jq run-time error is a jq program error, not
including syntax errors nor JSON text input format errors.
Examples:
With stdin and multiple lines:
$ printf '{"a":43}\n{"a":{"b":66}}\n' | ./jq '.a+1'
44
jq: error (at stdin:2): object and number cannot be added
With multiple files:
$ printf '{"a":43}' > 1.json
$ printf '{"a":"hello"}\n' > 2.json
$ printf '{"a":{"b":66}}\n' > 3.json
$ ./jq '[.a]|@tsv' 1.json 2.json 3.json
"43"
"hello"
jq: error (at 3.json:1): object is not valid in a csv row
With very long lines (spanning multiple `fgets` calls):
$ ( printf '{"a":43}\n' ;
printf '{"a":{"b":[' ; seq 10000 | paste -d, -s | tr -d '\n' ;
printf ']}}\n' ;
printf '{"a":"hello"}\n' ) | ./jq '[.a] | @tsv'
"43"
jq: error (at stdin:2): object is not valid in a csv row
"hello"
With raw input:
$ seq 1000 | ./jq --raw-input 'select(.=="700") | . + 10'
jq: error (at stdin:700): string and number cannot be added
Caveat:
The reported line will be the last line of the (valid) parsed JSON data.
Example:
$ printf '{\n"a":\n"hello"\n\n\n}\n' | ./jq '.a+4'
jq: error (at stdin:6): string and number cannot be added
