shared/json library

Checked access to a decoded response body.

HttpService's verbs hand back whatever jsonDecode produced, so every parser downstream is one unchecked cast away from a TypeError raised from inside the SDK - which reads as an SDK bug rather than as a response that was not the shape the endpoint promised. FindResultDto, Response.fromJson, _cacheUser and decodeToken each grew their own version of this check; this is the same idea in one place, for the cases that had none.

Functions

asJsonObject(dynamic body, String what) → Map<String, dynamic>
body as a JSON object, or a FormatException naming what arrived instead.
optionalDateTime(Map<String, dynamic> json, String key, String what) → DateTime?
The DateTime at key when there is one, null when the field is absent, and a FormatException when it is present but not a date.
optionalString(Map<String, dynamic> json, String key, String what) → String?
The string at key when there is one, null when the field is absent or null, and a FormatException when it is present as something other than a string.
optionalStringList(Map<String, dynamic> json, String key, String what) → List<String>?
The strings at key when there are any, null when the field is absent, and a FormatException when it is present as something other than a list of strings.
requireDateTime(Map<String, dynamic> json, String key, String what) → DateTime
The DateTime at key, or a FormatException naming the field.
requireString(Map<String, dynamic> json, String key, String what, {bool allowEmpty = false}) → String
The string at key, or a FormatException naming the field that was wrong.