tier 0.1.17

Rust configuration library for layered TOML, env, and CLI settings
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

use std::collections::BTreeSet;

use crate::ConfigError;
use crate::metadata::paths::validate_metadata_path;
use crate::metadata::{ConfigMetadata, FieldMetadata, ValidationRule};

pub(super) fn validate_field(
    metadata: &ConfigMetadata,
    field: &FieldMetadata,
) -> Result<(), ConfigError> {
    validate_metadata_path(&field.path)?;
    validate_root_restrictions(field)?;
    validate_source_policy(field)?;
    validate_validation_configs(metadata, field)?;
    validate_aliases(field)
}

fn validate_aliases(field: &FieldMetadata) -> Result<(), ConfigError> {
    for alias in &field.aliases {
        validate_metadata_path(alias)?;
        if alias.is_empty() {
            return Err(ConfigError::MetadataInvalid {
                path: alias.clone(),
                message: "aliases cannot target the root path".to_owned(),
            });
        }
    }
    Ok(())
}

fn validate_root_restrictions(field: &FieldMetadata) -> Result<(), ConfigError> {
    if field.path.is_empty() && !field.aliases.is_empty() {
        let alias = field.aliases.first().cloned().unwrap_or_default();
        return Err(ConfigError::MetadataInvalid {
            path: alias,
            message: "aliases cannot rewrite the root path".to_owned(),
        });
    }
    if field.path.is_empty() && field.merge_explicit {
        return Err(root_error(
            field,
            "merge strategies cannot target the root path",
        ));
    }
    if field.path.is_empty() && field.allowed_sources.is_some() {
        return Err(root_error(
            field,
            "source policies cannot target the root path",
        ));
    }
    if field.path.is_empty() && field.denied_sources.is_some() {
        return Err(root_error(
            field,
            "source policies cannot target the root path",
        ));
    }
    if field.path.is_empty() && !field.validations.is_empty() {
        return Err(root_error(
            field,
            "validation rules cannot target the root path",
        ));
    }
    if field.path.is_empty() && !field.validation_configs.is_empty() {
        return Err(root_error(
            field,
            "validation rules cannot target the root path",
        ));
    }
    if field.path.is_empty() && field.secret {
        return Err(root_error(
            field,
            "secret metadata cannot target the root path",
        ));
    }
    if field.path.is_empty() && field.deprecated.is_some() {
        return Err(root_error(
            field,
            "deprecation metadata cannot target the root path",
        ));
    }
    if field.path.is_empty() && field.env_decode.is_some() {
        return Err(root_error(
            field,
            "environment decoder paths cannot target the root path",
        ));
    }
    Ok(())
}

fn root_error(field: &FieldMetadata, message: &str) -> ConfigError {
    ConfigError::MetadataInvalid {
        path: field.path.clone(),
        message: message.to_owned(),
    }
}

fn validate_source_policy(field: &FieldMetadata) -> Result<(), ConfigError> {
    if let Some(allowed_sources) = &field.allowed_sources
        && allowed_sources.is_empty()
    {
        return Err(ConfigError::MetadataInvalid {
            path: field.path.clone(),
            message: "source policies must allow at least one source kind".to_owned(),
        });
    }
    if let Some(denied_sources) = &field.denied_sources
        && let Some(allowed_sources) = &field.allowed_sources
    {
        let overlap = allowed_sources
            .intersection(denied_sources)
            .copied()
            .collect::<Vec<_>>();
        if !overlap.is_empty() {
            return Err(ConfigError::MetadataInvalid {
                path: field.path.clone(),
                message: format!(
                    "source policies cannot both allow and deny the same source kinds: {}",
                    overlap
                        .iter()
                        .map(ToString::to_string)
                        .collect::<Vec<_>>()
                        .join(", ")
                ),
            });
        }
    }

    Ok(())
}

fn validate_validation_configs(
    metadata: &ConfigMetadata,
    field: &FieldMetadata,
) -> Result<(), ConfigError> {
    let effective_rule_codes = metadata
        .effective_field_for(&field.path)
        .map(|field| {
            field
                .validations
                .iter()
                .map(ValidationRule::code)
                .collect::<BTreeSet<_>>()
        })
        .unwrap_or_default();
    for rule_code in field.validation_configs.keys() {
        if !effective_rule_codes.contains(rule_code.as_str()) {
            return Err(ConfigError::MetadataInvalid {
                path: field.path.clone(),
                message: format!(
                    "validation config references unknown rule `{rule_code}` for this field"
                ),
            });
        }
    }

    Ok(())
}