Content-Type matching is too strict / doesn't follow matcher specification

[alexeits]

Given the pact JSON with term matcher on Content-Type header:

"response": {
  "status": 200,
  "headers": {
    "Content-Type": "text/plain"
  },
  "body": "fake-header.fake-token.fake-signature",
  "matchingRules": {
    "$.headers.Content-Type": {
      "match": "regex",
      "regex": "^text\\/plain"
    },
    "$.body": {
      "match": "regex",
      "regex": "^[^.]+.[^.]+.[^.]+$"
    }
  }
}

Complete JSON: demo-loader-auth.json

and the provider responding with

HTTP/1.1 200 OK
Connection: close
Content-Type: text/plain; charset=utf-8

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE3MTE2NTEyMjEsImlhdCI6MTcxMTY0NDAyMSwidG9waWNQZXJtaXNzaW9ucyI6ImVKeUtqZ1VFQUFELy93RVZBTGs9IiwidXNlcklkIjoic2FnYW5BZG1pbiIsIm9yZ0lkIjoic2FnYW4iLCJyb2xlSWRzIjpbInNhZ2FuLWFkbWluIl0sInNhZ2FuVXNlciI6InNhZ2FuLW9wZXJhdG9yIiwic2Vzc2lvbiI6eyJpZCI6IiJ9fQ.GaDrAz1132zOptIyElUp8-vSUkTZn47lFTGrzBKSycw

which matches Content-Type regex: https://regex101.com/r/eaiKgC/2

the corresponding pactffi trace:

RequestResponseInteraction { id: None, description: "create admin token for valid operator token", provider_states: [ProviderState { name: "operator has valid token", params: {} }], request: Request { method: "POST", path: "/api/v1/admin_tokens", query: None, headers: Some({"Content-Type": ["application/json"]}), body: Present(b"{\"token\":\"1234567890abcdef1234567890abcdef12345678\",\"username\":\"sagan-operator\"}", None, None), matching_rules: MatchingRules { rules: {} }, generators: Generators { categories: {} } }, response: Response { status: 200, headers: Some({"Content-Type": ["text/plain"]}), body: Present(b"fake-header.fake-token.fake-signature", Some(ContentType { main_type: "text", sub_type: "plain", attributes: {}, suffix: None }), None), matching_rules: MatchingRules { rules: {HEADER: MatchingRuleCategory { name: HEADER, rules: {DocPath { path_tokens: [Root, Field("Content-Type")], expr: "Content-Type" }: RuleList { rules: [Regex("^text\\/plain")], rule_logic: And, cascaded: false }} }, BODY: MatchingRuleCategory { name: BODY, rules: {DocPath { path_tokens: [Root], expr: "$" }: RuleList { rules: [Regex("^[^.]+.[^.]+.[^.]+$")], rule_logic: And, cascaded: false }} }} }, generators: Generators { categories: {} } } }

the verification fails with:

5) Verifying a pact between demo-loader and auth Given operator has valid token - create admin token for valid operator token
    5.1) includes header 'Content-Type' with value 'text/plain'
           Expected header 'Content-Type' to have value 'text/plain' but was 'text/plain; charset=utf-8'

This issue is present in libpact_ffi 0.4.16.

[rholshausen]

Just change your regex to ^text/plain(;.*)? and it will match

[alexeits]

@rholshausen TYVM for the tip. I confirm that it works.

Still arguably the behavior is unexpected because normally ^text/plain regex should match all strings that start with that prefix.