# Filters ## Definition [Captures] and [asserts] share a common structure: query. A query is used to extract data from an HTTP response; this data can come from the HTTP response body, the HTTP response headers or from the HTTP meta-informations (like `duration` for instance)... In this example, the query __`jsonpath "$.books[0].name"`__ is used in a capture to save data and in an assert to test the HTTP response body. __Capture__:

namevariable : jsonpath "$.books[0].name"query

__Assert__:

jsonpath "$.books[0].name"query == "Dune"predicate

In both case, the query is exactly the same: queries are the core structure of asserts and captures. Sometimes, you want to process data extracted by queries: that's the purpose of __filters__. Filters are used to transform value extracted by a query and can be used in asserts and captures to refine data. Filters __can be chained__, allowing for fine-grained data extraction.

jsonpath "$.name"query split "," nth 02 filters == "Herbert"predicate

## Example ```hurl GET https://example.org/api HTTP 200 [Captures] name: jsonpath "$user.id" replace /\d/ "x" [Asserts] header "x-servers" split "," count == 2 header "x-servers" split "," nth 0 == "rec1" header "x-servers" split "," nth 1 == "rec3" jsonpath "$.books" count == 12 ``` ## Description ### count Counts the number of items in a collection. ```hurl GET https://example.org/api HTTP 200 [Asserts] jsonpath "$.books" count == 12 ``` ### daysAfterNow Returns the number of days between now and a date in the future. ```hurl GET https://example.org HTTP 200 [Asserts] certificate "Expire-Date" daysAfterNow > 15 ``` ### daysBeforeNow Returns the number of days between now and a date in the past. ```hurl GET https://example.org HTTP 200 [Asserts] certificate "Start-Date" daysBeforeNow < 100 ``` ### decode Decode bytes to string using encoding. ```hurl # The 'Content-Type' HTTP response header does not precise the charset 'gb2312' # so body must be decoded explicitly by Hurl before processing any text based assert GET https://exapple.org/hello_china HTTP 200 [Asserts] header "Content-Type" == "text/html" # Content-Type has no encoding clue, we must decode ourselves the body response. bytes decode "gb2312" xpath "string(//body)" == "你好世界" ``` ### format Formats a date to a string given [a specification format]. ```hurl GET https://example.org HTTP 200 [Asserts] cookie "LSID[Expires]" format "%a, %d %b %Y %H:%M:%S" == "Wed, 13 Jan 2021 22:23:01" ``` ### htmlEscape Converts the characters `&`, `<` and `>` to HTML-safe sequence. ```hurl GET https://example.org/api HTTP 200 [Asserts] jsonpath "$.text" htmlEscape == "a > b" ``` ### htmlUnescape Converts all named and numeric character references (e.g. `>`, `>`, `>`) to the corresponding Unicode characters. ```hurl GET https://example.org/api HTTP 200 [Asserts] jsonpath "$.escaped_html[1]" htmlUnescape == "Foo © bar 𝌆" ``` ### jsonpath Evaluates a [JSONPath] expression. ```hurl GET https://example.org/api HTTP 200 [Captures] books: xpath "string(//body/@data-books)" [Asserts] variable "books" jsonpath "$[0].name" == "Dune" variable "books" jsonpath "$[0].author" == "Franck Herbert" ``` ### nth Returns the element from a collection at a zero-based index. ```hurl GET https://example.org/api HTTP 200 [Asserts] jsonpath "$.books" nth 2 == "Children of Dune" ``` ### regex Extracts regex capture group. Pattern must have at least one capture group. ```hurl GET https://example.org/foo HTTP 200 [Captures] param1: header "header1" param2: header "header2" regex "Hello (.*)!" param3: header "header2" regex /Hello (.*)!/ ``` ### replace Replaces all occurrences of old string with new string. ```hurl GET https://example.org/foo HTTP 200 [Captures] url: jsonpath "$.url" replace "http://" "https://" [Asserts] jsonpath "$.ips" replace ", " "|" == "192.168.2.1|10.0.0.20|10.0.0.10" ``` ### split Splits to a list of strings around occurrences of the specified delimiter. ```hurl GET https://example.org/foo HTTP 200 [Asserts] jsonpath "$.ips" split ", " count == 3 ``` ### toDate Converts a string to a date given [a specification format]. ```hurl GET https:///example.org HTTP 200 [Asserts] header "Expires" toDate "%a, %d %b %Y %H:%M:%S GMT" daysBeforeNow > 1000 ``` ISO 8601 / RFC 3339 date and time format have shorthand format `%+`: ```hurl GET https://example.org/api/books HTTP 200 [Asserts] jsonpath "$.published" == "2023-01-23T18:25:43.511Z" jsonpath "$.published" toDate "%Y-%m-%dT%H:%M:%S%.fZ" format "%A" == "Monday" jsonpath "$.published" toDate "%+" format "%A" == "Monday" # %+ can be used to parse ISO 8601 / RFC 3339 ``` ### toInt Converts to integer number. ```hurl GET https://example.org/foo HTTP 200 [Asserts] jsonpath "$.id" toInt == 123 ``` ### urlDecode Replaces %xx escapes with their single-character equivalent. ```hurl GET https://example.org/foo HTTP 200 [Asserts] jsonpath "$.encoded_url" urlDecode == "https://mozilla.org/?x=шеллы" ``` ### urlEncode Percent-encodes all the characters which are not included in unreserved chars (see [RFC3986]) with the exception of forward slash (/). ```hurl GET https://example.org/foo HTTP 200 [Asserts] jsonpath "$.url" urlEncode == "https%3A//mozilla.org/%3Fx%3D%D1%88%D0%B5%D0%BB%D0%BB%D1%8B" ``` ### xpath Evaluates a [XPath] expression. ```hurl GET https://example.org/hello_gb2312 HTTP 200 [Asserts] bytes decode "gb2312" xpath "string(//body)" == "你好世界" ``` [Captures]: /docs/capturing-response.md [asserts]: /docs/asserting-response.md [RFC3986]: https://www.rfc-editor.org/rfc/rfc3986 [a specification format]: https://docs.rs/chrono/latest/chrono/format/strftime/index.html [XPath]: https://en.wikipedia.org/wiki/XPath [JSONPath]: https://goessner.net/articles/JsonPath/