relay_event_schema/protocol/

stacktrace.rs

use std::convert::Infallible;
use std::fmt;
use std::ops::{Deref, DerefMut};
use std::str::FromStr;

use relay_protocol::{
    Annotated, Array, Empty, ErrorKind, FromValue, IntoValue, Object, SkipSerialization, Value,
};
use serde::{Deserialize, Serialize};

use crate::processor::ProcessValue;
use crate::protocol::{Addr, LockReason, NativeImagePath, RegVal};

/// Holds information about a single stacktrace frame.
///
/// Each object should contain **at least** a `filename`, `function` or `instruction_addr`
/// attribute. All values are optional, but recommended.
#[derive(Clone, Debug, Default, PartialEq, Empty, FromValue, IntoValue, ProcessValue)]
#[metastructure(process_func = "process_frame", value_type = "Frame")]
pub struct Frame {
    /// Name of the frame's function. This might include the name of a class.
    ///
    /// This function name may be shortened or demangled. If not, Sentry will demangle and shorten
    /// it for some platforms. The original function name will be stored in `raw_function`.
    #[metastructure(max_chars = 256, max_chars_allowance = 20)]
    #[metastructure(skip_serialization = "empty")]
    pub function: Annotated<String>,

    /// A raw (but potentially truncated) function value.
    ///
    /// The original function name, if the function name is shortened or demangled. Sentry shows the
    /// raw function when clicking on the shortened one in the UI.
    ///
    /// If this has the same value as `function` it's best to be omitted.  This exists because on
    /// many platforms the function itself contains additional information like overload specifies
    /// or a lot of generics which can make it exceed the maximum limit we provide for the field.
    /// In those cases then we cannot reliably trim down the function any more at a later point
    /// because the more valuable information has been removed.
    ///
    /// The logic to be applied is that an intelligently trimmed function name should be stored in
    /// `function` and the value before trimming is stored in this field instead.  However also this
    /// field will be capped at 256 characters at the moment which often means that not the entire
    /// original value can be stored.
    #[metastructure(max_chars = 256, max_chars_allowance = 20)]
    #[metastructure(skip_serialization = "empty")]
    pub raw_function: Annotated<String>,

    /// Potentially mangled name of the symbol as it appears in an executable.
    ///
    /// This is different from a function name by generally being the mangled
    /// name that appears natively in the binary.  This is relevant for languages
    /// like Swift, C++ or Rust.
    // XXX(markus): How is this different from just storing the mangled function name in
    // `function`?
    #[metastructure(max_chars = 256)]
    pub symbol: Annotated<String>,

    /// Name of the module the frame is contained in.
    ///
    /// Note that this might also include a class name if that is something the
    /// language natively considers to be part of the stack (for instance in Java).
    #[metastructure(skip_serialization = "empty", pii = "maybe")]
    // TODO: Cap? This can be a FS path or a dotted path
    pub module: Annotated<String>,

    /// Name of the package that contains the frame.
    ///
    /// For instance this can be a dylib for native languages, the name of the jar
    /// or .NET assembly.
    #[metastructure(skip_serialization = "empty")]
    // TODO: Cap? This can be a FS path or a dotted path
    pub package: Annotated<String>,

    /// The source file name (basename only).
    #[metastructure(max_chars = 256, max_chars_allowance = 40)]
    #[metastructure(skip_serialization = "empty", pii = "maybe")]
    pub filename: Annotated<NativeImagePath>,

    /// Absolute path to the source file.
    #[metastructure(max_chars = 256, max_chars_allowance = 40)]
    #[metastructure(skip_serialization = "empty", pii = "maybe")]
    pub abs_path: Annotated<NativeImagePath>,

    /// Line number within the source file, starting at 1.
    #[metastructure(skip_serialization = "null")]
    pub lineno: Annotated<u64>,

    /// Column number within the source file, starting at 1.
    #[metastructure(skip_serialization = "null")]
    pub colno: Annotated<u64>,

    /// Which platform this frame is from.
    ///
    /// This can override the platform for a single frame. Otherwise, the platform of the event is
    /// assumed. This can be used for multi-platform stack traces, such as in React Native.
    #[metastructure(skip_serialization = "empty")]
    pub platform: Annotated<String>,

    /// Source code leading up to `lineno`.
    #[metastructure(skip_serialization = "empty")]
    pub pre_context: Annotated<Array<String>>,

    /// Source code of the current line (`lineno`).
    #[metastructure(skip_serialization = "null")]
    pub context_line: Annotated<String>,

    /// Source code of the lines after `lineno`.
    #[metastructure(skip_serialization = "empty")]
    pub post_context: Annotated<Array<String>>,

    /// Override whether this frame should be considered part of application code, or part of
    /// libraries/frameworks/dependencies.
    ///
    /// Setting this attribute to `false` causes the frame to be hidden/collapsed by default and
    /// mostly ignored during issue grouping.
    #[metastructure(skip_serialization = "null")]
    pub in_app: Annotated<bool>,

    /// Mapping of local variables and expression names that were available in this frame.
    // XXX: Probably want to trim per-var => new bag size?
    #[metastructure(pii = "true", max_depth = 5, max_bytes = 2048)]
    pub vars: Annotated<FrameVars>,

    /// Auxiliary information about the frame that is platform specific.
    #[metastructure(omit_from_schema)]
    #[metastructure(skip_serialization = "empty")]
    pub data: Annotated<FrameData>,

    /// (C/C++/Native) Start address of the containing code module (image).
    #[metastructure(skip_serialization = "null")]
    pub image_addr: Annotated<Addr>,

    /// (C/C++/Native) An optional instruction address for symbolication.
    ///
    /// This should be a string with a hexadecimal number that includes a 0x prefix.
    /// If this is set and a known image is defined in the
    /// [Debug Meta Interface]({%- link _documentation/development/sdk-dev/event-payloads/debugmeta.md -%}),
    /// then symbolication can take place.
    #[metastructure(skip_serialization = "null")]
    pub instruction_addr: Annotated<Addr>,

    /// Defines the addressing mode for addresses.
    ///
    /// This can be:
    /// - `"abs"` (the default): `instruction_addr` is absolute.
    /// - `"rel:$idx"`: `instruction_addr` is relative to the `debug_meta.image` identified by its index in the list.
    /// - `"rel:$uuid"`: `instruction_addr` is relative to the `debug_meta.image` identified by its `debug_id`.
    ///
    /// If one of the `"rel:XXX"` variants is given together with `function_id`, the `instruction_addr` is relative
    /// to the uniquely identified function in the references `debug_meta.image`.
    #[metastructure(skip_serialization = "empty")]
    pub addr_mode: Annotated<String>,

    /// (.NET) The function id / index that uniquely identifies a function inside a module.
    ///
    /// This is the `MetadataToken` of a .NET `MethodBase`.
    #[metastructure(skip_serialization = "empty")]
    pub function_id: Annotated<Addr>,

    /// (C/C++/Native) Start address of the frame's function.
    ///
    /// We use the instruction address for symbolication, but this can be used to calculate
    /// an instruction offset automatically.
    #[metastructure(skip_serialization = "null")]
    pub symbol_addr: Annotated<Addr>,

    /// (C/C++/Native) Used for native crashes to indicate how much we can "trust" the instruction_addr
    #[metastructure(max_chars = 128)]
    #[metastructure(omit_from_schema)]
    pub trust: Annotated<String>,

    /// The language of the frame if it overrides the stacktrace language.
    #[metastructure(max_chars = 128)]
    #[metastructure(omit_from_schema)]
    pub lang: Annotated<String>,

    /// Marks this frame as the bottom of a chained stack trace.
    ///
    /// Stack traces from asynchronous code consist of several sub traces that are chained together
    /// into one large list. This flag indicates the root function of a chained stack trace.
    /// Depending on the runtime and thread, this is either the `main` function or a thread base
    /// stub.
    ///
    /// This field should only be specified when true.
    #[metastructure(skip_serialization = "null")]
    pub stack_start: Annotated<bool>,

    /// A possible lock (java monitor object) held by this frame.
    #[metastructure(skip_serialization = "null")]
    pub lock: Annotated<LockReason>,

    /// Additional arbitrary fields for forwards compatibility.
    #[metastructure(additional_properties)]
    pub other: Object<Value>,
}

/// Frame local variables.
#[derive(Clone, Debug, Default, PartialEq, Empty, IntoValue, ProcessValue)]
pub struct FrameVars(#[metastructure(skip_serialization = "empty")] pub Object<Value>);

/// Additional frame data information.
///
/// This value is set by the server and should not be set by the SDK.
#[derive(Clone, Debug, Default, PartialEq, Empty, FromValue, IntoValue, ProcessValue)]
pub struct FrameData {
    /// A reference to the sourcemap used.
    #[metastructure(max_chars = 256, max_chars_allowance = 40)]
    sourcemap: Annotated<String>,
    /// The original function name before it was resolved.
    #[metastructure(max_chars = 256, max_chars_allowance = 20)]
    orig_function: Annotated<String>,
    /// The original minified filename.
    #[metastructure(max_chars = 256, max_chars_allowance = 40)]
    orig_filename: Annotated<String>,
    /// The original line number.
    orig_lineno: Annotated<u64>,
    /// The original column number.
    orig_colno: Annotated<u64>,
    /// The original value of the in_app flag before grouping enhancers ran.
    ///
    /// Because we need to handle more cases the following values are used:
    ///
    /// - missing / `null`: information not available
    /// - `-1`: in_app was set to `null`
    /// - `0`: in_app was set to `false`
    /// - `1`: in_app was set to `true`
    orig_in_app: Annotated<i64>,
    /// Additional keys not handled by this protocol.
    #[metastructure(additional_properties)]
    pub other: Object<Value>,
}

impl From<Object<Value>> for FrameVars {
    fn from(value: Object<Value>) -> Self {
        FrameVars(value)
    }
}

impl FromValue for FrameVars {
    fn from_value(mut value: Annotated<Value>) -> Annotated<FrameVars> {
        value = value.map_value(|value| {
            if let Value::Array(value) = value {
                Value::Object(
                    value
                        .into_iter()
                        .enumerate()
                        .map(|(i, v)| (i.to_string(), v))
                        .collect(),
                )
            } else {
                value
            }
        });

        FromValue::from_value(value).map_value(FrameVars)
    }
}

/// A stack trace of a single thread.
///
/// A stack trace contains a list of frames, each with various bits (most optional) describing the
/// context of that frame. Frames should be sorted from oldest to newest.
///
/// For the given example program written in Python:
///
/// ```python
/// def foo():
///     my_var = 'foo'
///     raise ValueError()
///
/// def main():
///     foo()
/// ```
///
/// A minimalistic stack trace for the above program in the correct order:
///
/// ```json
/// {
///   "frames": [
///     {"function": "main"},
///     {"function": "foo"}
///   ]
/// }
/// ```
///
/// The top frame fully symbolicated with five lines of source context:
///
/// ```json
/// {
///   "frames": [{
///     "in_app": true,
///     "function": "myfunction",
///     "abs_path": "/real/file/name.py",
///     "filename": "file/name.py",
///     "lineno": 3,
///     "vars": {
///       "my_var": "'value'"
///     },
///     "pre_context": [
///       "def foo():",
///       "  my_var = 'foo'",
///     ],
///     "context_line": "  raise ValueError()",
///     "post_context": [
///       "",
///       "def main():"
///     ],
///   }]
/// }
/// ```
///
/// A minimal native stack trace with register values. Note that the `package` event attribute must
/// be "native" for these frames to be symbolicated.
///
/// ```json
/// {
///   "frames": [
///     {"instruction_addr": "0x7fff5bf3456c"},
///     {"instruction_addr": "0x7fff5bf346c0"},
///   ],
///   "registers": {
///     "rip": "0x00007ff6eef54be2",
///     "rsp": "0x0000003b710cd9e0"
///   }
/// }
/// ```
#[derive(Clone, Debug, Default, PartialEq, Empty, FromValue, IntoValue, ProcessValue)]
#[metastructure(process_func = "process_raw_stacktrace", value_type = "Stacktrace")]
pub struct RawStacktrace {
    /// Required. A non-empty list of stack frames. The list is ordered from caller to callee, or
    /// oldest to youngest. The last frame is the one creating the exception.
    #[metastructure(required = true, nonempty = true, skip_serialization = "empty")]
    pub frames: Annotated<Array<Frame>>,

    /// Register values of the thread (top frame).
    ///
    /// A map of register names and their values. The values should contain the actual register
    /// values of the thread, thus mapping to the last frame in the list.
    pub registers: Annotated<Object<RegVal>>,

    /// Optional. A flag that indicates if, and how, `instruction_addr` values need to be adjusted
    /// before they are symbolicated.
    #[metastructure(skip_serialization = "null")]
    pub instruction_addr_adjustment: Annotated<InstructionAddrAdjustment>,

    /// The language of the stacktrace.
    #[metastructure(max_chars = 128)]
    pub lang: Annotated<String>,

    /// Indicates that this stack trace is a snapshot triggered by an external signal.
    ///
    /// If this field is `false`, then the stack trace points to the code that caused this stack
    /// trace to be created. This can be the location of a raised exception, as well as an exception
    /// or signal handler.
    ///
    /// If this field is `true`, then the stack trace was captured as part of creating an unrelated
    /// event. For example, a thread other than the crashing thread, or a stack trace computed as a
    /// result of an external kill signal.
    pub snapshot: Annotated<bool>,

    /// Additional arbitrary fields for forwards compatibility.
    #[metastructure(additional_properties)]
    pub other: Object<Value>,
}

/// Controls the mechanism by which the `instruction_addr` of a [`Stacktrace`] [`Frame`] is adjusted.
///
/// The adjustment tries to transform *return addresses* to *call addresses* for symbolication.
/// Typically, this adjustment needs to be done for all frames but the first, as the first frame is
/// usually taken directly from the cpu context of a hardware exception or a suspended thread and
/// the stack trace is created from that.
///
/// When the stack walking implementation truncates frames from the top, `"all"` frames should be
/// adjusted. In case the stack walking implementation already does the adjustment when producing
/// stack frames, `"none"` should be used here.
#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize, ProcessValue)]
#[serde(rename_all = "snake_case")]
pub enum InstructionAddrAdjustment {
    /// The default. Applies a heuristic based on other event / exception attributes.
    Auto,

    /// All but the first frame needs to be adjusted. The first frame's address is not a *return address*,
    /// but points directly to the faulty instruction.
    AllButFirst,

    /// All frames should be adjusted, for example because the stack walking implementation truncated
    /// frames from the top of the stack, and all remaining frames' addresses are *return addresses*.
    All,

    /// The stack walking implementation already provides correct addresses and no adjustment should
    /// be performed when symbolicating.
    None,

    /// Any other unknown adjustment strategy.
    ///
    /// This exists to ensure forward compatibility.
    Unknown(String),
}

impl InstructionAddrAdjustment {
    /// Returns the string representation of this adjustment.
    pub fn as_str(&self) -> &str {
        match self {
            InstructionAddrAdjustment::Auto => "auto",
            InstructionAddrAdjustment::AllButFirst => "all_but_first",
            InstructionAddrAdjustment::All => "all",
            InstructionAddrAdjustment::None => "none",
            InstructionAddrAdjustment::Unknown(s) => s,
        }
    }
}

impl FromStr for InstructionAddrAdjustment {
    type Err = Infallible;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s {
            "auto" => Ok(Self::Auto),
            "all_but_first" => Ok(Self::AllButFirst),
            "all" => Ok(Self::All),
            "none" => Ok(Self::None),
            s => Ok(Self::Unknown(s.to_string())),
        }
    }
}

impl fmt::Display for InstructionAddrAdjustment {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.write_str(self.as_str())
    }
}

impl Default for InstructionAddrAdjustment {
    fn default() -> Self {
        Self::Auto
    }
}

impl Empty for InstructionAddrAdjustment {
    #[inline]
    fn is_empty(&self) -> bool {
        matches!(self, Self::Auto)
    }
}

impl FromValue for InstructionAddrAdjustment {
    fn from_value(value: Annotated<Value>) -> Annotated<Self> {
        match String::from_value(value) {
            Annotated(Some(value), mut meta) => match value.parse() {
                Ok(adjustment) => Annotated(Some(adjustment), meta),
                Err(_) => {
                    meta.add_error(ErrorKind::InvalidData);
                    meta.set_original_value(Some(value));
                    Annotated(None, meta)
                }
            },
            Annotated(None, meta) => Annotated(None, meta),
        }
    }
}

impl IntoValue for InstructionAddrAdjustment {
    fn into_value(self) -> Value
    where
        Self: Sized,
    {
        Value::String(match self {
            Self::Unknown(s) => s,
            _ => self.as_str().to_owned(),
        })
    }

    fn serialize_payload<S>(&self, s: S, _behavior: SkipSerialization) -> Result<S::Ok, S::Error>
    where
        Self: Sized,
        S: serde::Serializer,
    {
        serde::Serialize::serialize(self.as_str(), s)
    }
}

// NOTE: This is not a doc comment because otherwise it will show up in public docs.
// Newtype to distinguish `raw_stacktrace` attributes from the rest.
#[derive(Clone, Debug, Default, PartialEq, Empty, FromValue, IntoValue, ProcessValue)]
#[metastructure(process_func = "process_stacktrace")]
pub struct Stacktrace(pub RawStacktrace);

impl Deref for Stacktrace {
    type Target = RawStacktrace;

    fn deref(&self) -> &RawStacktrace {
        &self.0
    }
}

impl DerefMut for Stacktrace {
    fn deref_mut(&mut self) -> &mut RawStacktrace {
        &mut self.0
    }
}

impl From<RawStacktrace> for Stacktrace {
    fn from(stacktrace: RawStacktrace) -> Stacktrace {
        Stacktrace(stacktrace)
    }
}

impl From<Stacktrace> for RawStacktrace {
    fn from(stacktrace: Stacktrace) -> RawStacktrace {
        stacktrace.0
    }
}

#[cfg(test)]
mod tests {
    use crate::protocol::{LockReasonType, ThreadId};
    use similar_asserts::assert_eq;

    use super::*;

    #[test]
    fn test_frame_roundtrip() {
        let json = r#"{
  "function": "main@8",
  "raw_function": "main",
  "symbol": "_main@8",
  "module": "app",
  "package": "/my/app",
  "filename": "myfile.rs",
  "abs_path": "/path/to",
  "lineno": 2,
  "colno": 42,
  "platform": "rust",
  "pre_context": [
    "fn main() {"
  ],
  "context_line": "unimplemented!()",
  "post_context": [
    "}"
  ],
  "in_app": true,
  "vars": {
    "variable": "value"
  },
  "data": {
    "sourcemap": "http://example.com/invalid.map"
  },
  "image_addr": "0x400",
  "instruction_addr": "0x404",
  "addr_mode": "abs",
  "symbol_addr": "0x404",
  "trust": "69",
  "lang": "rust",
  "stack_start": true,
  "lock": {
    "type": 2,
    "address": "0x07d7437b",
    "package_name": "io.sentry.samples",
    "class_name": "MainActivity",
    "thread_id": 7
  },
  "other": "value"
}"#;
        let frame = Annotated::new(Frame {
            function: Annotated::new("main@8".to_string()),
            raw_function: Annotated::new("main".to_string()),
            symbol: Annotated::new("_main@8".to_string()),
            module: Annotated::new("app".to_string()),
            package: Annotated::new("/my/app".to_string()),
            filename: Annotated::new("myfile.rs".into()),
            abs_path: Annotated::new("/path/to".into()),
            lineno: Annotated::new(2),
            colno: Annotated::new(42),
            platform: Annotated::new("rust".to_string()),
            pre_context: Annotated::new(vec![Annotated::new("fn main() {".to_string())]),
            context_line: Annotated::new("unimplemented!()".to_string()),
            post_context: Annotated::new(vec![Annotated::new("}".to_string())]),
            in_app: Annotated::new(true),
            vars: {
                let mut vars = Object::new();
                vars.insert(
                    "variable".to_string(),
                    Annotated::new(Value::String("value".to_string())),
                );
                Annotated::new(vars.into())
            },
            data: Annotated::new(FrameData {
                sourcemap: Annotated::new("http://example.com/invalid.map".to_string()),
                ..Default::default()
            }),
            image_addr: Annotated::new(Addr(0x400)),
            instruction_addr: Annotated::new(Addr(0x404)),
            addr_mode: Annotated::new("abs".into()),
            function_id: Annotated::empty(),
            symbol_addr: Annotated::new(Addr(0x404)),
            trust: Annotated::new("69".into()),
            lang: Annotated::new("rust".into()),
            stack_start: Annotated::new(true),
            lock: Annotated::new(LockReason {
                ty: Annotated::new(LockReasonType::Waiting),
                address: Annotated::new("0x07d7437b".to_string()),
                package_name: Annotated::new("io.sentry.samples".to_string()),
                class_name: Annotated::new("MainActivity".to_string()),
                thread_id: Annotated::new(ThreadId::Int(7)),
                other: Default::default(),
            }),
            other: {
                let mut vars = Object::new();
                vars.insert(
                    "other".to_string(),
                    Annotated::new(Value::String("value".to_string())),
                );
                vars
            },
        });

        assert_eq!(frame, Annotated::from_json(json).unwrap());
        assert_eq!(json, frame.to_json_pretty().unwrap());
    }

    #[test]
    fn test_frame_default_values() {
        let json = "{}";
        let frame = Annotated::new(Frame::default());

        assert_eq!(frame, Annotated::from_json(json).unwrap());
        assert_eq!(json, frame.to_json_pretty().unwrap());
    }

    #[test]
    fn test_stacktrace_roundtrip() {
        let json = r#"{
  "frames": [
    {
      "function": "foobar"
    }
  ],
  "registers": {
    "cspr": "0x20000000",
    "lr": "0x18a31aadc",
    "pc": "0x18a310ea4",
    "sp": "0x16fd75060"
  },
  "instruction_addr_adjustment": "all_but_first",
  "lang": "rust",
  "snapshot": false,
  "other": "value"
}"#;
        let stack = Annotated::new(RawStacktrace {
            frames: Annotated::new(vec![Annotated::new(Frame {
                function: Annotated::new("foobar".to_string()),
                ..Default::default()
            })]),
            registers: {
                let mut registers = Object::new();
                registers.insert("cspr".to_string(), Annotated::new(RegVal(0x2000_0000)));
                registers.insert("lr".to_string(), Annotated::new(RegVal(0x1_8a31_aadc)));
                registers.insert("pc".to_string(), Annotated::new(RegVal(0x1_8a31_0ea4)));
                registers.insert("sp".to_string(), Annotated::new(RegVal(0x1_6fd7_5060)));
                Annotated::new(registers)
            },
            instruction_addr_adjustment: Annotated::new(InstructionAddrAdjustment::AllButFirst),
            lang: Annotated::new("rust".into()),
            snapshot: Annotated::new(false),
            other: {
                let mut other = Object::new();
                other.insert(
                    "other".to_string(),
                    Annotated::new(Value::String("value".to_string())),
                );
                other
            },
        });

        assert_eq!(stack, Annotated::from_json(json).unwrap());
        assert_eq!(json, stack.to_json_pretty().unwrap());
    }

    #[test]
    fn test_stacktrace_default_values() {
        // This needs an empty frame because "frames" is required
        let json = r#"{
  "frames": [
    {}
  ]
}"#;

        let stack = Annotated::new(RawStacktrace {
            frames: Annotated::new(vec![Annotated::new(Frame::default())]),
            ..Default::default()
        });

        assert_eq!(stack, Annotated::from_json(json).unwrap());
        assert_eq!(json, stack.to_json_pretty().unwrap());
    }

    #[test]
    fn test_frame_vars_null_preserved() {
        let json = r#"{
  "vars": {
    "despacito": null
  }
}"#;
        let frame = Annotated::new(Frame {
            vars: Annotated::new({
                let mut vars = Object::new();
                vars.insert("despacito".to_string(), Annotated::empty());
                vars.into()
            }),
            ..Default::default()
        });

        assert_eq!(Annotated::from_json(json).unwrap(), frame);
        assert_eq!(json, frame.to_json_pretty().unwrap());
    }

    #[test]
    fn test_frame_vars_empty_annotated_is_serialized() {
        let output = r#"{
  "vars": {
    "despacito": null,
    "despacito2": null
  }
}"#;
        let frame = Annotated::new(Frame {
            vars: Annotated::new({
                let mut vars = Object::new();
                vars.insert("despacito".to_string(), Annotated::empty());
                vars.insert("despacito2".to_string(), Annotated::empty());
                vars.into()
            }),
            ..Default::default()
        });

        assert_eq!(output, frame.to_json_pretty().unwrap());
    }

    #[test]
    fn test_frame_empty_context_lines() {
        let json = r#"{
  "pre_context": [
    ""
  ],
  "context_line": "",
  "post_context": [
    ""
  ]
}"#;

        let frame = Annotated::new(Frame {
            pre_context: Annotated::new(vec![Annotated::new("".to_string())]),
            context_line: Annotated::new("".to_string()),
            post_context: Annotated::new(vec![Annotated::new("".to_string())]),
            ..Frame::default()
        });

        assert_eq!(frame, Annotated::from_json(json).unwrap());
        assert_eq!(json, frame.to_json_pretty().unwrap());
    }

    #[test]
    fn test_php_frame_vars() {
        // Buggy PHP SDKs send us this stuff
        //
        // Port of https://github.com/getsentry/sentry/commit/73d9a061dcac3ab8c318a09735601a12e81085dd

        let input = r#"{
  "vars": ["foo", "bar", "baz", null]
}"#;

        let output = r#"{
  "vars": {
    "0": "foo",
    "1": "bar",
    "2": "baz",
    "3": null
  }
}"#;

        let frame = Annotated::new(Frame {
            vars: Annotated::new({
                let mut vars = Object::new();
                vars.insert("0".to_string(), Annotated::new("foo".to_string().into()));
                vars.insert("1".to_string(), Annotated::new("bar".to_string().into()));
                vars.insert("2".to_string(), Annotated::new("baz".to_string().into()));
                vars.insert("3".to_string(), Annotated::empty());
                vars.into()
            }),
            ..Default::default()
        });

        assert_eq!(frame, Annotated::from_json(input).unwrap());
        assert_eq!(output, frame.to_json_pretty().unwrap());
    }
}