diff --git a/crates/workflow/src/trigger.rs b/crates/workflow/src/trigger.rs
--- a/crates/workflow/src/trigger.rs
+++ b/crates/workflow/src/trigger.rs
@@ -1,238 +1,245 @@
-use std::fmt;
-
-use thiserror::Error;
-
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
-pub enum EventKind {
-    Push,
-    PullRequest,
-    Manual,
-    Schedule,
-}
-
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub enum GitReference {
-    Branch(String),
-    Tag(String),
-}
-
-/// What happened, as much of it as deciding needs: which kind, on which Git
-/// reference, and which paths it touched.
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Event {
-    kind: EventKind,
-    reference: GitReference,
-    changed_paths: Vec<String>,
-}
-
-#[derive(Clone, Debug, Default, Eq, PartialEq)]
-pub struct Filter {
-    include: Vec<Pattern>,
-    exclude: Vec<Pattern>,
-}
-
-/// A subset of the glob syntax the dialect allows: literals, `*` within one
-/// segment, and `**` across segments. Anything else is refused rather than
-/// matched by accident.
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Pattern(String);
-
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Trigger {
-    kind: EventKind,
-    branches: Filter,
-    tags: Filter,
-    paths: Filter,
-}
-
-#[derive(Clone, Debug, Default, Eq, PartialEq)]
-pub struct Triggers(Vec<Trigger>);
-
-#[derive(Debug, Error)]
-pub enum TriggerError {
-    #[error("pattern {0:?} uses glob syntax this compiler does not support")]
-    UnsupportedPattern(String),
-}
-
-impl Event {
-    #[must_use]
-    pub fn new(kind: EventKind, reference: GitReference, changed_paths: Vec<String>) -> Self {
-        Self {
-            kind,
-            reference,
-            changed_paths,
-        }
-    }
-
-    #[must_use]
-    pub const fn kind(&self) -> EventKind {
-        self.kind
-    }
-
-    #[must_use]
-    pub const fn reference(&self) -> &GitReference {
-        &self.reference
-    }
-}
-
-impl GitReference {
-    #[must_use]
-    pub fn name(&self) -> &str {
-        match self {
-            Self::Branch(name) | Self::Tag(name) => name,
-        }
-    }
-
-    #[must_use]
-    pub fn full_name(&self) -> String {
-        match self {
-            Self::Branch(name) => format!("refs/heads/{name}"),
-            Self::Tag(name) => format!("refs/tags/{name}"),
-        }
-    }
-}
-
-impl Pattern {
-    pub fn parse(value: &str) -> Result<Self, TriggerError> {
-        if value.contains(['?', '[', ']', '+', '!']) {
-            return Err(TriggerError::UnsupportedPattern(value.to_owned()));
-        }
-        Ok(Self(value.to_owned()))
-    }
-
-    #[must_use]
-    pub fn matches(&self, candidate: &str) -> bool {
-        matches_from(&self.0, candidate)
-    }
-}
-
-fn matches_from(pattern: &str, candidate: &str) -> bool {
-    match pattern.find('*') {
-        None => pattern == candidate,
-        Some(position) => {
-            let (literal, rest) = pattern.split_at(position);
-            if !candidate.starts_with(literal) {
-                return false;
-            }
-            let candidate = &candidate[literal.len()..];
-            if let Some(rest) = rest.strip_prefix("**") {
-                (0..=candidate.len()).any(|skip| matches_from(rest, &candidate[skip..]))
-            } else {
-                let rest = &rest[1..];
-                candidate
-                    .char_indices()
-                    .take_while(|(_, character)| *character != '/')
-                    .map(|(index, character)| index + character.len_utf8())
-                    .chain(std::iter::once(0))
-                    .any(|skip| matches_from(rest, &candidate[skip..]))
-            }
-        }
-    }
-}
-
-impl Filter {
-    #[must_use]
-    pub const fn new(include: Vec<Pattern>, exclude: Vec<Pattern>) -> Self {
-        Self { include, exclude }
-    }
-
-    /// Nothing stated means everything passes. An exclusion always wins, which
-    /// is what makes `paths-ignore` mean what it says.
-    #[must_use]
-    pub fn admits(&self, candidate: &str) -> bool {
-        if self
-            .exclude
-            .iter()
-            .any(|pattern| pattern.matches(candidate))
-        {
-            return false;
-        }
-        self.include.is_empty()
-            || self
-                .include
-                .iter()
-                .any(|pattern| pattern.matches(candidate))
-    }
-
-    #[must_use]
-    pub fn is_empty(&self) -> bool {
-        self.include.is_empty() && self.exclude.is_empty()
-    }
-}
-
-impl Trigger {
-    #[must_use]
-    pub const fn new(kind: EventKind, branches: Filter, tags: Filter, paths: Filter) -> Self {
-        Self {
-            kind,
-            branches,
-            tags,
-            paths,
-        }
-    }
-
-    fn matches_kind_and_reference(&self, event: &Event) -> bool {
-        if self.kind != event.kind {
-            return false;
-        }
-        match event.reference() {
-            GitReference::Branch(branch) => {
-                (self.tags.is_empty() || !self.branches.is_empty()) && self.branches.admits(branch)
-            }
-            GitReference::Tag(tag) => {
-                (self.branches.is_empty() || !self.tags.is_empty()) && self.tags.admits(tag)
-            }
-        }
-    }
-
-    #[must_use]
-    pub fn fires_on(&self, event: &Event) -> bool {
-        if !self.matches_kind_and_reference(event) {
-            return false;
-        }
-        // A path filter on an event that touched nothing has nothing to admit,
-        // so it does not fire.
-        self.paths.is_empty()
-            || event
-                .changed_paths
-                .iter()
-                .any(|path| self.paths.admits(path))
-    }
-}
-
-impl Triggers {
-    #[must_use]
-    pub const fn new(triggers: Vec<Trigger>) -> Self {
-        Self(triggers)
-    }
-
-    /// A workflow with no `on:` is never triggered by an event. Saying nothing
-    /// is not saying everything.
-    #[must_use]
-    pub fn fire_on(&self, event: &Event) -> bool {
-        self.0.iter().any(|trigger| trigger.fires_on(event))
-    }
-
-    #[must_use]
-    pub fn may_fire_on(&self, event: &Event) -> bool {
-        self.0
-            .iter()
-            .any(|trigger| trigger.matches_kind_and_reference(event))
-    }
-
-    #[must_use]
-    pub fn is_empty(&self) -> bool {
-        self.0.is_empty()
-    }
-}
-
-impl fmt::Display for EventKind {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Push => formatter.write_str("push"),
-            Self::PullRequest => formatter.write_str("pull_request"),
-            Self::Manual => formatter.write_str("workflow_dispatch"),
-            Self::Schedule => formatter.write_str("schedule"),
-        }
-    }
-}
+use std::fmt;
+
+use thiserror::Error;
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum EventKind {
+    Push,
+    PullRequest,
+    Manual,
+    Schedule,
+}
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum GitReference {
+    Branch(String),
+    Tag(String),
+}
+
+/// What happened, as much of it as deciding needs: which kind, on which Git
+/// reference, and which paths it touched.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Event {
+    kind: EventKind,
+    reference: GitReference,
+    changed_paths: Vec<String>,
+}
+
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct Filter {
+    include: Vec<Pattern>,
+    exclude: Vec<Pattern>,
+}
+
+/// A subset of the glob syntax the dialect allows: literals, `*` within one
+/// segment, and `**` across segments. Anything else is refused rather than
+/// matched by accident.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Pattern(String);
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Trigger {
+    kind: EventKind,
+    branches: Filter,
+    tags: Filter,
+    paths: Filter,
+}
+
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct Triggers(Vec<Trigger>);
+
+#[derive(Debug, Error)]
+pub enum TriggerError {
+    #[error("pattern {0:?} uses glob syntax this compiler does not support")]
+    UnsupportedPattern(String),
+}
+
+impl Event {
+    #[must_use]
+    pub fn new(kind: EventKind, reference: GitReference, changed_paths: Vec<String>) -> Self {
+        Self {
+            kind,
+            reference,
+            changed_paths,
+        }
+    }
+
+    #[must_use]
+    pub const fn kind(&self) -> EventKind {
+        self.kind
+    }
+
+    #[must_use]
+    pub const fn reference(&self) -> &GitReference {
+        &self.reference
+    }
+}
+
+impl GitReference {
+    #[must_use]
+    pub fn name(&self) -> &str {
+        match self {
+            Self::Branch(name) | Self::Tag(name) => name,
+        }
+    }
+
+    #[must_use]
+    pub fn full_name(&self) -> String {
+        match self {
+            Self::Branch(name) => format!("refs/heads/{name}"),
+            Self::Tag(name) => format!("refs/tags/{name}"),
+        }
+    }
+}
+
+impl Pattern {
+    pub fn parse(value: &str) -> Result<Self, TriggerError> {
+        if value.contains(['?', '[', ']', '+', '!']) {
+            return Err(TriggerError::UnsupportedPattern(value.to_owned()));
+        }
+        Ok(Self(value.to_owned()))
+    }
+
+    #[must_use]
+    pub fn matches(&self, candidate: &str) -> bool {
+        matches_from(&self.0, candidate)
+    }
+}
+
+fn matches_from(pattern: &str, candidate: &str) -> bool {
+    match pattern.find('*') {
+        None => pattern == candidate,
+        Some(position) => {
+            let (literal, rest) = pattern.split_at(position);
+            if !candidate.starts_with(literal) {
+                return false;
+            }
+            let candidate = &candidate[literal.len()..];
+            if let Some(rest) = rest.strip_prefix("**") {
+                (0..=candidate.len()).any(|skip| matches_from(rest, &candidate[skip..]))
+            } else {
+                let rest = &rest[1..];
+                candidate
+                    .char_indices()
+                    .take_while(|(_, character)| *character != '/')
+                    .map(|(index, character)| index + character.len_utf8())
+                    .chain(std::iter::once(0))
+                    .any(|skip| matches_from(rest, &candidate[skip..]))
+            }
+        }
+    }
+}
+
+impl Filter {
+    #[must_use]
+    pub const fn new(include: Vec<Pattern>, exclude: Vec<Pattern>) -> Self {
+        Self { include, exclude }
+    }
+
+    /// Nothing stated means everything passes. An exclusion always wins, which
+    /// is what makes `paths-ignore` mean what it says.
+    #[must_use]
+    pub fn admits(&self, candidate: &str) -> bool {
+        if self
+            .exclude
+            .iter()
+            .any(|pattern| pattern.matches(candidate))
+        {
+            return false;
+        }
+        self.include.is_empty()
+            || self
+                .include
+                .iter()
+                .any(|pattern| pattern.matches(candidate))
+    }
+
+    #[must_use]
+    pub fn is_empty(&self) -> bool {
+        self.include.is_empty() && self.exclude.is_empty()
+    }
+}
+
+impl Trigger {
+    #[must_use]
+    pub const fn new(kind: EventKind, branches: Filter, tags: Filter, paths: Filter) -> Self {
+        Self {
+            kind,
+            branches,
+            tags,
+            paths,
+        }
+    }
+
+    fn matches_kind_and_reference(&self, event: &Event) -> bool {
+        if self.kind != event.kind {
+            return false;
+        }
+        match event.reference() {
+            GitReference::Branch(branch) => {
+                (self.tags.is_empty() || !self.branches.is_empty()) && self.branches.admits(branch)
+            }
+            GitReference::Tag(tag) => {
+                (self.branches.is_empty() || !self.tags.is_empty()) && self.tags.admits(tag)
+            }
+        }
+    }
+
+    #[must_use]
+    pub fn fires_on(&self, event: &Event) -> bool {
+        if !self.matches_kind_and_reference(event) {
+            return false;
+        }
+        // A path filter on an event that touched nothing has nothing to admit,
+        // so it does not fire.
+        self.paths.is_empty()
+            || event
+                .changed_paths
+                .iter()
+                .any(|path| self.paths.admits(path))
+    }
+}
+
+impl Triggers {
+    #[must_use]
+    pub const fn new(triggers: Vec<Trigger>) -> Self {
+        Self(triggers)
+    }
+
+    /// A workflow with no `on:` is never triggered by an event. Saying nothing
+    /// is not saying everything.
+    #[must_use]
+    pub fn fire_on(&self, event: &Event) -> bool {
+        self.0.iter().any(|trigger| trigger.fires_on(event))
+    }
+
+    #[must_use]
+    pub fn may_fire_on(&self, event: &Event) -> bool {
+        self.0
+            .iter()
+            .any(|trigger| trigger.matches_kind_and_reference(event))
+    }
+
+    #[must_use]
+    pub fn needs_changed_paths(&self, event: &Event) -> bool {
+        self.0
+            .iter()
+            .any(|trigger| trigger.matches_kind_and_reference(event) && !trigger.paths.is_empty())
+    }
+
+    #[must_use]
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+}
+
+impl fmt::Display for EventKind {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Push => formatter.write_str("push"),
+            Self::PullRequest => formatter.write_str("pull_request"),
+            Self::Manual => formatter.write_str("workflow_dispatch"),
+            Self::Schedule => formatter.write_str("schedule"),
+        }
+    }
+}
diff --git a/crates/workflow/tests/trigger.rs b/crates/workflow/tests/trigger.rs
--- a/crates/workflow/tests/trigger.rs
+++ b/crates/workflow/tests/trigger.rs
@@ -1,189 +1,205 @@
-#![allow(clippy::expect_used, clippy::panic, clippy::unwrap_used)]
-
-use syncode_workflow::{Event, EventKind, Filter, GitReference, Pattern, Trigger, Triggers};
-
-fn pattern(value: &str) -> Pattern {
-    Pattern::parse(value).unwrap_or_else(|error| panic!("pattern {value}: {error}"))
-}
-
-fn patterns(values: &[&str]) -> Vec<Pattern> {
-    values.iter().copied().map(pattern).collect()
-}
-
-fn push(branch: &str, paths: &[&str]) -> Event {
-    Event::new(
-        EventKind::Push,
-        GitReference::Branch(branch.to_owned()),
-        paths.iter().map(|path| (*path).to_owned()).collect(),
-    )
-}
-
-#[test]
-fn a_workflow_that_says_nothing_is_never_triggered() {
-    assert!(!Triggers::default().fire_on(&push("main", &["src/main.rs"])));
-}
-
-#[test]
-fn a_branch_filter_decides_which_pushes_count() {
-    let triggers = Triggers::new(vec![Trigger::new(
-        EventKind::Push,
-        Filter::new(patterns(&["main", "release/*"]), Vec::new()),
-        Filter::default(),
-        Filter::default(),
-    )]);
-
-    assert!(triggers.fire_on(&push("main", &[])));
-    assert!(triggers.fire_on(&push("release/0.3", &[])));
-    assert!(!triggers.fire_on(&push("feature/x", &[])));
-    assert!(
-        !triggers.fire_on(&push("release/0.3/hotfix", &[])),
-        "a single star does not cross a slash"
-    );
-}
-
-#[test]
-fn a_double_star_crosses_slashes() {
-    let triggers = Triggers::new(vec![Trigger::new(
-        EventKind::Push,
-        Filter::new(patterns(&["release/**"]), Vec::new()),
-        Filter::default(),
-        Filter::default(),
-    )]);
-
-    assert!(triggers.fire_on(&push("release/0.3", &[])));
-    assert!(triggers.fire_on(&push("release/0.3/hotfix", &[])));
-}
-
-#[test]
-fn an_exclusion_wins_over_an_inclusion() {
-    let triggers = Triggers::new(vec![Trigger::new(
-        EventKind::Push,
-        Filter::new(patterns(&["**"]), patterns(&["wip/**"])),
-        Filter::default(),
-        Filter::default(),
-    )]);
-
-    assert!(triggers.fire_on(&push("main", &[])));
-    assert!(!triggers.fire_on(&push("wip/experiment", &[])));
-}
-
-#[test]
-fn a_path_filter_needs_a_touched_path_to_admit() {
-    let triggers = Triggers::new(vec![Trigger::new(
-        EventKind::Push,
-        Filter::default(),
-        Filter::default(),
-        Filter::new(patterns(&["crates/**"]), Vec::new()),
-    )]);
-
-    assert!(triggers.fire_on(&push("main", &["crates/workflow/src/lib.rs"])));
-    assert!(!triggers.fire_on(&push("main", &["README.md"])));
-    assert!(
-        !triggers.fire_on(&push("main", &[])),
-        "an event that touched nothing has nothing for a path filter to admit"
-    );
-}
-
-#[test]
-fn kind_and_branch_can_reject_an_event_before_paths_are_loaded() {
-    let triggers = Triggers::new(vec![Trigger::new(
-        EventKind::Push,
-        Filter::new(patterns(&["main"]), Vec::new()),
-        Filter::default(),
-        Filter::new(patterns(&["crates/**"]), Vec::new()),
-    )]);
-
-    assert!(!triggers.may_fire_on(&push("feature/x", &[])));
-    assert!(triggers.may_fire_on(&push("main", &[])));
-    assert!(!triggers.fire_on(&push("main", &[])));
-}
-
-#[test]
-fn ignored_paths_do_not_trigger_on_their_own() {
-    let triggers = Triggers::new(vec![Trigger::new(
-        EventKind::Push,
-        Filter::default(),
-        Filter::default(),
-        Filter::new(Vec::new(), patterns(&["**.md"])),
-    )]);
-
-    assert!(!triggers.fire_on(&push("main", &["README.md"])));
-    assert!(
-        triggers.fire_on(&push("main", &["README.md", "src/main.rs"])),
-        "one path outside the ignore list is enough"
-    );
-}
-
-#[test]
-fn an_event_of_another_kind_does_not_fire_the_trigger() {
-    let triggers = Triggers::new(vec![Trigger::new(
-        EventKind::PullRequest,
-        Filter::default(),
-        Filter::default(),
-        Filter::default(),
-    )]);
-
-    assert!(!triggers.fire_on(&push("main", &["src/main.rs"])));
-    assert!(triggers.fire_on(&Event::new(
-        EventKind::PullRequest,
-        GitReference::Branch("main".to_owned()),
-        vec!["src/main.rs".to_owned()],
-    )));
-}
-
-#[test]
-fn branch_and_tag_filters_are_distinct() {
-    let triggers = Triggers::new(vec![Trigger::new(
-        EventKind::Push,
-        Filter::new(patterns(&["main"]), Vec::new()),
-        Filter::new(patterns(&["v*"]), Vec::new()),
-        Filter::default(),
-    )]);
-
-    assert!(triggers.fire_on(&push("main", &[])));
-    assert!(!triggers.fire_on(&push("feature/x", &[])));
-    assert!(triggers.fire_on(&Event::new(
-        EventKind::Push,
-        GitReference::Tag("v0.4.0".to_owned()),
-        Vec::new(),
-    )));
-    assert!(!triggers.fire_on(&Event::new(
-        EventKind::Push,
-        GitReference::Tag("release-candidate".to_owned()),
-        Vec::new(),
-    )));
-}
-
-#[test]
-fn a_filter_for_one_reference_kind_excludes_the_other_kind() {
-    let branches = Triggers::new(vec![Trigger::new(
-        EventKind::Push,
-        Filter::new(patterns(&["main"]), Vec::new()),
-        Filter::default(),
-        Filter::default(),
-    )]);
-    let tags = Triggers::new(vec![Trigger::new(
-        EventKind::Push,
-        Filter::default(),
-        Filter::new(patterns(&["v*"]), Vec::new()),
-        Filter::default(),
-    )]);
-
-    let tag = Event::new(
-        EventKind::Push,
-        GitReference::Tag("v0.4.0".to_owned()),
-        Vec::new(),
-    );
-    assert!(!branches.fire_on(&tag));
-    assert!(!tags.fire_on(&push("main", &[])));
-}
-
-#[test]
-fn glob_syntax_this_compiler_does_not_support_is_refused() {
-    let error = Pattern::parse("release/[0-9]*").expect_err("character classes are not supported");
-
-    assert!(
-        error.to_string().contains("does not support"),
-        "unexpected error: {error}"
-    );
-}
+#![allow(clippy::expect_used, clippy::panic, clippy::unwrap_used)]
+
+use syncode_workflow::{Event, EventKind, Filter, GitReference, Pattern, Trigger, Triggers};
+
+fn pattern(value: &str) -> Pattern {
+    Pattern::parse(value).unwrap_or_else(|error| panic!("pattern {value}: {error}"))
+}
+
+fn patterns(values: &[&str]) -> Vec<Pattern> {
+    values.iter().copied().map(pattern).collect()
+}
+
+fn push(branch: &str, paths: &[&str]) -> Event {
+    Event::new(
+        EventKind::Push,
+        GitReference::Branch(branch.to_owned()),
+        paths.iter().map(|path| (*path).to_owned()).collect(),
+    )
+}
+
+#[test]
+fn a_workflow_that_says_nothing_is_never_triggered() {
+    assert!(!Triggers::default().fire_on(&push("main", &["src/main.rs"])));
+}
+
+#[test]
+fn a_branch_filter_decides_which_pushes_count() {
+    let triggers = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::new(patterns(&["main", "release/*"]), Vec::new()),
+        Filter::default(),
+        Filter::default(),
+    )]);
+
+    assert!(triggers.fire_on(&push("main", &[])));
+    assert!(triggers.fire_on(&push("release/0.3", &[])));
+    assert!(!triggers.fire_on(&push("feature/x", &[])));
+    assert!(
+        !triggers.fire_on(&push("release/0.3/hotfix", &[])),
+        "a single star does not cross a slash"
+    );
+}
+
+#[test]
+fn a_double_star_crosses_slashes() {
+    let triggers = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::new(patterns(&["release/**"]), Vec::new()),
+        Filter::default(),
+        Filter::default(),
+    )]);
+
+    assert!(triggers.fire_on(&push("release/0.3", &[])));
+    assert!(triggers.fire_on(&push("release/0.3/hotfix", &[])));
+}
+
+#[test]
+fn an_exclusion_wins_over_an_inclusion() {
+    let triggers = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::new(patterns(&["**"]), patterns(&["wip/**"])),
+        Filter::default(),
+        Filter::default(),
+    )]);
+
+    assert!(triggers.fire_on(&push("main", &[])));
+    assert!(!triggers.fire_on(&push("wip/experiment", &[])));
+}
+
+#[test]
+fn a_path_filter_needs_a_touched_path_to_admit() {
+    let triggers = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::default(),
+        Filter::default(),
+        Filter::new(patterns(&["crates/**"]), Vec::new()),
+    )]);
+
+    assert!(triggers.fire_on(&push("main", &["crates/workflow/src/lib.rs"])));
+    assert!(!triggers.fire_on(&push("main", &["README.md"])));
+    assert!(
+        !triggers.fire_on(&push("main", &[])),
+        "an event that touched nothing has nothing for a path filter to admit"
+    );
+}
+
+#[test]
+fn kind_and_branch_can_reject_an_event_before_paths_are_loaded() {
+    let triggers = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::new(patterns(&["main"]), Vec::new()),
+        Filter::default(),
+        Filter::new(patterns(&["crates/**"]), Vec::new()),
+    )]);
+
+    assert!(!triggers.may_fire_on(&push("feature/x", &[])));
+    assert!(triggers.may_fire_on(&push("main", &[])));
+    assert!(!triggers.needs_changed_paths(&push("feature/x", &[])));
+    assert!(triggers.needs_changed_paths(&push("main", &[])));
+    assert!(!triggers.fire_on(&push("main", &[])));
+}
+
+#[test]
+fn a_pathless_trigger_does_not_need_changed_paths() {
+    let triggers = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::new(patterns(&["main"]), Vec::new()),
+        Filter::default(),
+        Filter::default(),
+    )]);
+
+    assert!(triggers.may_fire_on(&push("main", &[])));
+    assert!(!triggers.needs_changed_paths(&push("main", &[])));
+    assert!(triggers.fire_on(&push("main", &[])));
+}
+
+#[test]
+fn ignored_paths_do_not_trigger_on_their_own() {
+    let triggers = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::default(),
+        Filter::default(),
+        Filter::new(Vec::new(), patterns(&["**.md"])),
+    )]);
+
+    assert!(!triggers.fire_on(&push("main", &["README.md"])));
+    assert!(
+        triggers.fire_on(&push("main", &["README.md", "src/main.rs"])),
+        "one path outside the ignore list is enough"
+    );
+}
+
+#[test]
+fn an_event_of_another_kind_does_not_fire_the_trigger() {
+    let triggers = Triggers::new(vec![Trigger::new(
+        EventKind::PullRequest,
+        Filter::default(),
+        Filter::default(),
+        Filter::default(),
+    )]);
+
+    assert!(!triggers.fire_on(&push("main", &["src/main.rs"])));
+    assert!(triggers.fire_on(&Event::new(
+        EventKind::PullRequest,
+        GitReference::Branch("main".to_owned()),
+        vec!["src/main.rs".to_owned()],
+    )));
+}
+
+#[test]
+fn branch_and_tag_filters_are_distinct() {
+    let triggers = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::new(patterns(&["main"]), Vec::new()),
+        Filter::new(patterns(&["v*"]), Vec::new()),
+        Filter::default(),
+    )]);
+
+    assert!(triggers.fire_on(&push("main", &[])));
+    assert!(!triggers.fire_on(&push("feature/x", &[])));
+    assert!(triggers.fire_on(&Event::new(
+        EventKind::Push,
+        GitReference::Tag("v0.4.0".to_owned()),
+        Vec::new(),
+    )));
+    assert!(!triggers.fire_on(&Event::new(
+        EventKind::Push,
+        GitReference::Tag("release-candidate".to_owned()),
+        Vec::new(),
+    )));
+}
+
+#[test]
+fn a_filter_for_one_reference_kind_excludes_the_other_kind() {
+    let branches = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::new(patterns(&["main"]), Vec::new()),
+        Filter::default(),
+        Filter::default(),
+    )]);
+    let tags = Triggers::new(vec![Trigger::new(
+        EventKind::Push,
+        Filter::default(),
+        Filter::new(patterns(&["v*"]), Vec::new()),
+        Filter::default(),
+    )]);
+
+    let tag = Event::new(
+        EventKind::Push,
+        GitReference::Tag("v0.4.0".to_owned()),
+        Vec::new(),
+    );
+    assert!(!branches.fire_on(&tag));
+    assert!(!tags.fire_on(&push("main", &[])));
+}
+
+#[test]
+fn glob_syntax_this_compiler_does_not_support_is_refused() {
+    let error = Pattern::parse("release/[0-9]*").expect_err("character classes are not supported");
+
+    assert!(
+        error.to_string().contains("does not support"),
+        "unexpected error: {error}"
+    );
+}