swc_common/plugin/
metadata.rs

1use std::env;
2
3use once_cell::sync::Lazy;
4use rustc_hash::FxHashMap;
5
6/// Indexable key to the metadata context for a transform plugin.
7///
8/// Avoiding serialization & allocation to the host by using incremental number.
9/// TransformPluginMetadataContext does not implement Index trait, instead
10/// host does manual matching to corresponding value.
11#[derive(Copy, Clone)]
12pub enum TransformPluginMetadataContextKind {
13    // This value always should increase, even if some keys are removed in the
14    // future.
15    Filename = 1,
16    Env = 2,
17    Cwd = 3,
18}
19
20impl From<u32> for TransformPluginMetadataContextKind {
21    fn from(key: u32) -> TransformPluginMetadataContextKind {
22        match key {
23            1 => TransformPluginMetadataContextKind::Filename,
24            2 => TransformPluginMetadataContextKind::Env,
25            3 => TransformPluginMetadataContextKind::Cwd,
26            _ => panic!("Invalid TransformPluginMetadataContextKind key"),
27        }
28    }
29}
30
31/// Host side metadata context plugin may need to access.
32/// This is a global context - any plugin in single transform will have same
33/// values.
34pub struct TransformPluginMetadataContext {
35    /// The path of the file being processed. This includes all of the path as
36    /// much as possible.
37    pub filename: Option<String>,
38    /// The current environment resolved as process.env.SWC_ENV ||
39    /// process.env.NODE_ENV || "development"
40    pub env: String,
41    /// The current working directory.
42    pub cwd: Option<String>,
43    pub experimental: FxHashMap<String, String>,
44}
45
46impl TransformPluginMetadataContext {
47    pub fn new(
48        filename: Option<String>,
49        env: String,
50        experimental: Option<FxHashMap<String, String>>,
51    ) -> Self {
52        static CWD: Lazy<Option<String>> = Lazy::new(|| {
53            env::current_dir()
54                .map(|cwd| cwd.as_path().to_string_lossy().to_string())
55                .ok()
56        });
57
58        TransformPluginMetadataContext {
59            filename,
60            env,
61            cwd: CWD.clone(),
62            experimental: experimental.unwrap_or_default(),
63        }
64    }
65
66    pub fn get(&self, key: &TransformPluginMetadataContextKind) -> Option<String> {
67        match key {
68            TransformPluginMetadataContextKind::Filename => self.filename.clone(),
69            TransformPluginMetadataContextKind::Env => Some(self.env.clone()),
70            TransformPluginMetadataContextKind::Cwd => self.cwd.clone(),
71        }
72    }
73}
swc_common/plugin/metadata.rs

swc_common/plugin/
metadata.rs
