dataflow-rs 3.11.0

A lightweight rules engine for building IFTTT-style automation and data processing pipelines in Rust. Define rules with JSONLogic conditions, execute actions, and chain workflows.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252

//! Fixtures shared by the integration test binaries.
//!
//! Every file directly under `tests/` compiles as its own crate, so anything
//! more than one of them needs lives here and is pulled in with `mod common;`.
//! No single binary uses all of it — hence the module-wide dead-code allowance.

#![allow(dead_code)]

use async_trait::async_trait;
use dataflow_rs::datalogic_rs::bumpalo::Bump;
use dataflow_rs::engine::functions::AsyncFunctionHandler;
use dataflow_rs::{Engine, Result, TaskContext, TaskOutcome, Template, TemplateCompiler, Workflow};
use datavalue::OwnedDataValue;
use serde_json::{Value, json};

/// Bridge helper for tests: build an `OwnedDataValue` from a `json!` literal.
pub fn dv(v: serde_json::Value) -> OwnedDataValue {
    OwnedDataValue::from(&v)
}

/// A `Workflow` from a `json!` literal.
pub fn workflow(definition: Value) -> Workflow {
    Workflow::from_json(&definition.to_string()).unwrap()
}

/// Evaluate `expr` against `data` on the engine's own datalogic instance —
/// the same path a handler calling `ctx.datalogic()` takes.
pub fn eval(engine: &Engine, expr: Value, data: Value) -> std::result::Result<Value, String> {
    let logic = engine
        .datalogic()
        .compile_arc(&expr)
        .map_err(|e| e.to_string())?;
    let arena = Bump::new();
    engine
        .datalogic()
        .evaluate(&logic, &data, &arena)
        .map(|v| serde_json::to_value(v).unwrap())
        .map_err(|e| e.to_string())
}

/// Uppercases its first argument — a stand-in custom operator.
pub struct Shout;

impl dataflow_rs::datalogic_rs::CustomOperator for Shout {
    fn evaluate<'a>(
        &self,
        args: &[&'a dataflow_rs::datalogic_rs::DataValue<'a>],
        _ctx: &mut dataflow_rs::datalogic_rs::operator::EvalContext<'_, 'a>,
        arena: &'a dataflow_rs::datalogic_rs::bumpalo::Bump,
    ) -> dataflow_rs::datalogic_rs::Result<&'a dataflow_rs::datalogic_rs::DataValue<'a>> {
        use dataflow_rs::datalogic_rs::ArenaExt;
        let s = args.first().and_then(|v| v.as_str()).unwrap_or_default();
        Ok(arena.string(&s.to_uppercase()))
    }
}

// -----------------------------------------------------------------------------
// Secrets — shared by `secrets.rs` and `secrets_isolation.rs`
// -----------------------------------------------------------------------------

/// Distinctive enough that a substring search is a real test.
pub const SECRET: &str = "s3cr3t-value-7f2a";
pub const NESTED: &str = "nested-hmac-91c0";

/// The store the secrets tests share: one top-level key and one nested.
pub fn secrets() -> Value {
    json!({
        "partner_key": SECRET,
        "partner": { "hmac": NESTED }
    })
}

#[derive(serde::Deserialize)]
pub struct SignInput {
    pub key: Template,
    pub body: Template,
}

/// The shape the store exists for: a handler reads the key through a
/// `Template` — in every projection the API offers — and writes only a
/// derived value, `data.sig = "<body length>:<key length>"`.
///
/// **Precondition:** the engine's store is [`secrets()`] and the task's `key`
/// resolves to [`SECRET`] — the projections are checked against that constant,
/// so registering `Sign` against any other store panics from inside the task
/// executor rather than failing the caller's own assertion.
pub struct Sign;

#[async_trait]
impl AsyncFunctionHandler for Sign {
    type Input = SignInput;

    fn compile_input(input: &mut Self::Input, c: &TemplateCompiler) -> Result<()> {
        input.key.compile(c, "key")?;
        input.body.compile(c, "body")
    }

    async fn execute(&self, ctx: &mut TaskContext<'_>, input: &Self::Input) -> Result<TaskOutcome> {
        let key: String = input.key.eval_into(ctx)?;
        assert_eq!(key, SECRET, "Template::eval_into");
        assert_eq!(input.key.eval(ctx)?, dv(json!(SECRET)), "Template::eval");
        assert_eq!(
            input.key.eval_to_plain_string(ctx)?,
            SECRET,
            "Template::eval_to_plain_string"
        );
        let body: String = input.body.eval_into(ctx)?;
        ctx.set(
            "data.sig",
            dv(json!(format!("{}:{}", body.len(), key.len()))),
        );
        Ok(TaskOutcome::Success)
    }
}

// A simple async task implementation
#[derive(Debug)]
pub struct LoggingTask;

#[async_trait]
impl AsyncFunctionHandler for LoggingTask {
    type Input = Value;

    async fn execute(&self, ctx: &mut TaskContext<'_>, _input: &Value) -> Result<TaskOutcome> {
        println!("Executed task for message: {}", ctx.message().id());
        Ok(TaskOutcome::Success)
    }
}

// Handler that always returns Err — used by the single-error-channel
// regression tests.
pub struct FailingTask;

#[async_trait]
impl AsyncFunctionHandler for FailingTask {
    type Input = Value;

    async fn execute(&self, _ctx: &mut TaskContext<'_>, _input: &Value) -> Result<TaskOutcome> {
        Err(dataflow_rs::DataflowError::Task("boom".to_string()))
    }
}

// Handler that returns a 500 status — used by the single-error-channel
// regression tests.
pub struct FivehundredTask;

#[async_trait]
impl AsyncFunctionHandler for FivehundredTask {
    type Input = Value;

    async fn execute(&self, _ctx: &mut TaskContext<'_>, _input: &Value) -> Result<TaskOutcome> {
        Ok(TaskOutcome::Status(500))
    }
}

// Handler that fails with an engine-owned variant carrying its own
// classification — used by the error-code tests, which pin that the live path
// records `TIMEOUT_ERROR` rather than collapsing every variant to `TASK_ERROR`.
pub struct TimingOutTask;

#[async_trait]
impl AsyncFunctionHandler for TimingOutTask {
    type Input = Value;

    async fn execute(&self, _ctx: &mut TaskContext<'_>, _input: &Value) -> Result<TaskOutcome> {
        Err(dataflow_rs::DataflowError::Timeout(
            "provider timed out".to_string(),
        ))
    }
}

// Handler that records an error and still succeeds. Reaches neither failure arm
// of `handle_task_result`, so it pins that the error-context path follows
// `message.errors()` rather than the failure arms.
pub struct AddErrorTask;

#[async_trait]
impl AsyncFunctionHandler for AddErrorTask {
    type Input = Value;

    async fn execute(&self, ctx: &mut TaskContext<'_>, _input: &Value) -> Result<TaskOutcome> {
        ctx.add_error(dataflow_rs::ErrorInfo::builder("CUSTOM_CODE", "handler-recorded").build());
        Ok(TaskOutcome::Success)
    }
}

// An async task implementation
pub struct AsyncLoggingTask;

#[async_trait]
impl AsyncFunctionHandler for AsyncLoggingTask {
    type Input = Value;

    async fn execute(&self, ctx: &mut TaskContext<'_>, _input: &Value) -> Result<TaskOutcome> {
        println!("Executed async task for message: {}", ctx.message().id());
        // Simulate async work
        tokio::time::sleep(tokio::time::Duration::from_millis(1)).await;
        Ok(TaskOutcome::Success)
    }
}

/// N map tasks, each writing one key, as one workflow.
pub fn n_map_task_workflow(n: usize) -> Workflow {
    let tasks: Vec<String> = (0..n)
        .map(|i| {
            format!(
                r#"{{ "id": "t{i}", "name": "t{i}", "function": {{
                       "name": "map",
                       "input": {{ "mappings": [ {{ "path": "data.k{i}", "logic": {i} }} ] }} }} }}"#
            )
        })
        .collect();
    Workflow::from_json(&format!(
        r#"{{ "id": "w", "name": "w", "priority": 0, "condition": true,
              "tasks": [{}] }}"#,
        tasks.join(",")
    ))
    .unwrap()
}

/// One recorded observer callback.
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct SeenEvent {
    pub workflow_id: String,
    pub task_id: String,
    pub function: String,
    pub status: Option<u16>,
}

/// Records every event it is handed. `Mutex` is fine for a test; a real observer
/// must not block, per the trait contract.
#[derive(Default)]
pub struct RecordingObserver {
    events: std::sync::Mutex<Vec<SeenEvent>>,
}

impl RecordingObserver {
    pub fn seen(&self) -> Vec<SeenEvent> {
        self.events.lock().unwrap().clone()
    }
}

impl dataflow_rs::ExecutionObserver for RecordingObserver {
    fn task_finished(&self, event: &dataflow_rs::TaskEvent<'_>) {
        self.events.lock().unwrap().push(SeenEvent {
            workflow_id: event.workflow_id.to_string(),
            task_id: event.task_id.to_string(),
            function: event.function.to_string(),
            status: event.status,
        });
    }
}