dtcs 0.3.0

Reference implementation of the Data Transformation Contract Standard (DTCS)
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

//! Rule model.

use serde::{Deserialize, Serialize};

use super::identifiers::is_vendor_namespaced_identifier;
use super::metadata::Metadata;

/// Rule evaluation phase per SPEC Chapter 19.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum RulePhase {
    /// Evaluated before execution.
    Precondition,
    /// Evaluated during execution.
    Execution,
    /// Evaluated after execution.
    Postcondition,
}

impl RulePhase {
    /// Returns the serialized phase name.
    #[must_use]
    pub fn as_str(self) -> &'static str {
        match self {
            Self::Precondition => "precondition",
            Self::Execution => "execution",
            Self::Postcondition => "postcondition",
        }
    }
}

/// A declarative invariant rule.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct Rule {
    /// Stable rule instance identifier.
    pub id: String,
    /// Rule registry identifier (for example `dtcs:not_null`).
    pub rule: String,
    /// Evaluation target.
    pub target: String,
    /// Evaluation phase.
    pub phase: RulePhase,
    /// Object metadata (SPEC Chapter 5 ยง3).
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub metadata: Option<Metadata>,
}

/// Known standard rules for MVP validation.
pub const KNOWN_RULES: &[&str] = &["dtcs:not_null"];

/// Returns `true` when the rule identifier is recognized.
#[must_use]
pub fn is_known_rule(rule: &str) -> bool {
    KNOWN_RULES.contains(&rule) || is_vendor_namespaced_identifier(rule)
}