feat(config): add config validation

src/config.rs

@@ -1,5 +1,6 @@
 use std::str::FromStr;
 
+use anyhow::{bail, Result};
 use regex::Regex;
 use serde_derive::Deserialize;
 use tracing::trace;
@@ -66,6 +67,36 @@ pub trait Act {
   fn apply_action(&self, input: &str) -> String;
 }
 
+impl Replacements<'_> {
+  pub fn validate(&self) -> Result<()> {
+    for subst in self.substitutors.iter() {
+      match &subst.matcher {
+        MatcherType::Single(matcher) => match matcher {
+          Matcher::Regex { pattern } => {
+            if let Err(e) = Regex::from_str(pattern) {
+              bail!(e);
+            }
+          }
+          _ => {}
+        },
+        MatcherType::Multiple(matchers) => {
+          for matcher in matchers.iter() {
+            match matcher {
+              Matcher::Regex { pattern } => {
+                if let Err(e) = Regex::from_str(pattern) {
+                  bail!(e);
+                }
+              }
+              _ => {}
+            }
+          }
+        }
+      }
+    }
+    Ok(())
+  }
+}
+
 impl Match for Matcher<'_> {
   fn check_match(&self, string: &str) -> bool {
     trace!(?self, ?string, "Checking for match");

src/test.rs

@@ -72,3 +72,27 @@ fn parse_with_single_matcher() {
   assert!(matches!(subst.matcher, MatcherType::Single(_)));
   assert!(matches!(subst.action, Action::Prefix { .. }));
 }
+
+#[assay]
+fn config_validation_success() {
+  let config = r#"
+[[substitutor]]
+name = "vxTwitter"
+matcher = { regex = { pattern = "^https://(?P<host>(?:mobile.)?twitter.com)/.*/status/[0-9]+.*" } }
+action = { replace = { from = "twitter.com", to = "vxtwitter.com" } }
+  "#;
+  let config: Replacements<'_> = toml::from_str(config)?;
+  assert!(matches!(config.validate(), Ok(_)));
+}
+
+#[assay]
+fn config_validation_failure() {
+  let config = r#"
+[[substitutor]]
+name = "vxTwitter"
+matcher = { regex = { pattern = "^https://(?P<>(?:mobile.)?twitter.com)/.*/status/[0-9]+.*" } }
+action = { replace = { from = "twitter.com", to = "vxtwitter.com" } }
+  "#;
+  let config: Replacements<'_> = toml::from_str(config)?;
+  assert!(matches!(config.validate(), Err(_)));
+}