feat: implement baseline query

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "vendor/caniuse"]
 	path = vendor/caniuse
 	url = https://github.com/Fyrd/caniuse.git
+[submodule "vendor/baseline-browser-mapping"]
+	path = vendor/baseline-browser-mapping
+	url = https://github.com/web-platform-dx/baseline-browser-mapping.git

README.md

@@ -44,7 +44,6 @@ The features below aren't supported currently:
 
 -   Custom usage like `> 0.5% in my stats`.
 -   Custom usage like `cover 99.5% in my stats`.
--   Baseline queries added in [browserslist v4.26.0](https://github.com/browserslist/browserslist/releases/tag/4.26.0) like `baseline widely available`.
 
 ## Local development setup
 

data/src/baseline.rs

@@ -0,0 +1,154 @@
+static BASELINE_WIDELY: &[(&str, &str)] = include!("generated/baseline-widely.rs");
+static BASELINE_NEWLY: &[(&str, &str)] = include!("generated/baseline-newly.rs");
+static BASELINE_YEARS: &[(u16, &str, &str)] = include!("generated/baseline-years.rs");
+// (cutoff_date, chrome, chrome_android, edge, firefox, firefox_android, safari, safari_ios)
+// Cumulative max min-versions, sorted by cutoff_date.
+static BASELINE_FEATURES: &[(&str, &str, &str, &str, &str, &str, &str, &str)] =
+    include!("generated/baseline-features.rs");
+include!("generated/baseline-downstream.rs");
+
+fn get_core_min_from_snapshot(
+    snapshot: (
+        &'static str,
+        &'static str,
+        &'static str,
+        &'static str,
+        &'static str,
+        &'static str,
+        &'static str,
+        &'static str,
+    ),
+    browser: &str,
+) -> Option<&'static str> {
+    let (_, c, ca, e, f, fa, s, si) = snapshot;
+    let v = match browser {
+        "chrome" => c,
+        "and_chr" => ca,
+        "edge" => e,
+        "firefox" => f,
+        "and_ff" => fa,
+        "safari" => s,
+        "ios_saf" => si,
+        _ => return None,
+    };
+    if v == "0" {
+        None
+    } else {
+        Some(v)
+    }
+}
+
+pub fn get_baseline_widely_min_version(browser: &str) -> Option<&'static str> {
+    BASELINE_WIDELY
+        .binary_search_by_key(&browser, |(b, _)| *b)
+        .ok()
+        .map(|i| BASELINE_WIDELY[i].1)
+}
+
+pub fn get_baseline_newly_min_version(browser: &str) -> Option<&'static str> {
+    BASELINE_NEWLY
+        .binary_search_by_key(&browser, |(b, _)| *b)
+        .ok()
+        .map(|i| BASELINE_NEWLY[i].1)
+}
+
+pub fn get_baseline_year_min_version(year: u16, browser: &str) -> Option<&'static str> {
+    // The CSV year Y for a version V means V is in the range [min_for_Y, min_for_{Y+1}).
+    // For baseline:YYYY, we want the minimum version = the first version in the smallest
+    // CSV year group Y where Y >= YYYY.
+    //
+    // Example: Chrome has no year=2018 group; Chrome 66 (year=2019) is the correct
+    // minimum for both baseline:2018 and baseline:2019.
+    // Example: Safari starts at year=2017; Safari 11 is the minimum for baseline:2015/2016/2017.
+    BASELINE_YEARS
+        .iter()
+        .filter(|(y, b, _)| *y >= year && *b == browser)
+        .min_by_key(|(y, _, _)| *y)
+        .map(|(_, _, v)| *v)
+}
+
+/// Returns the minimum version for a given browser as of a specific cutoff date.
+/// The cutoff_date is the `baseline_low_date` threshold (already with 30-month offset applied
+/// for widely-available queries).
+pub fn get_baseline_cutoff_date_min_version(
+    cutoff_date: &str,
+    browser: &str,
+) -> Option<&'static str> {
+    // Binary search for the largest entry with date <= cutoff_date.
+    // BASELINE_FEATURES is sorted by date strings (YYYY-MM-DD is lexicographically sortable).
+    let idx = BASELINE_FEATURES.partition_point(|(date, ..)| *date <= cutoff_date);
+
+    if idx == 0 {
+        return None;
+    }
+    get_core_min_from_snapshot(BASELINE_FEATURES[idx - 1], browser)
+}
+
+/// Returns the minimum version for a Blink-based downstream browser given the minimum
+/// Chrome (Blink) engine major version.
+pub fn get_downstream_blink_min_version(
+    chrome_min: &str,
+    caniuse_browser: &str,
+) -> Option<&'static str> {
+    let min_major: u16 = chrome_min.split('.').next()?.parse().ok()?;
+    // Find the minimum browser_version where engine_version >= min_major.
+    // Entries are not guaranteed monotone in (engine_version, browser_version) order,
+    // so we scan all entries for this browser.
+    BASELINE_DOWNSTREAM_BLINK
+        .iter()
+        .filter(|(b, ev, _)| *b == caniuse_browser && *ev >= min_major)
+        .min_by(|(_, _, va), (_, _, vb)| cmp_version(va, vb))
+        .map(|(_, _, v)| *v)
+}
+
+/// Returns the minimum version for a Gecko-based downstream browser given the minimum
+/// Firefox (Gecko) engine major version.
+pub fn get_downstream_gecko_min_version(
+    firefox_min: &str,
+    caniuse_browser: &str,
+) -> Option<&'static str> {
+    let min_major: u16 = firefox_min.split('.').next()?.parse().ok()?;
+    BASELINE_DOWNSTREAM_GECKO
+        .iter()
+        .filter(|(b, ev, _)| *b == caniuse_browser && *ev >= min_major)
+        .min_by(|(_, _, va), (_, _, vb)| cmp_version(va, vb))
+        .map(|(_, _, v)| *v)
+}
+
+fn cmp_version(a: &str, b: &str) -> std::cmp::Ordering {
+    let parse = |s: &str| -> (u64, u64) {
+        let mut parts = s.split('.');
+        let major = parts.next().and_then(|p| p.parse().ok()).unwrap_or(0);
+        let minor = parts.next().and_then(|p| p.parse().ok()).unwrap_or(0);
+        (major, minor)
+    };
+    parse(a).cmp(&parse(b))
+}
+
+/// Returns the caniuse browser names for Blink-based downstream browsers.
+pub fn blink_downstream_browsers() -> impl Iterator<Item = &'static str> {
+    let mut seen = std::collections::BTreeSet::new();
+    BASELINE_DOWNSTREAM_BLINK.iter().filter_map(
+        move |(b, _, _)| {
+            if seen.insert(*b) {
+                Some(*b)
+            } else {
+                None
+            }
+        },
+    )
+}
+
+/// Returns the caniuse browser names for Gecko-based downstream browsers.
+pub fn gecko_downstream_browsers() -> impl Iterator<Item = &'static str> {
+    let mut seen = std::collections::BTreeSet::new();
+    BASELINE_DOWNSTREAM_GECKO.iter().filter_map(
+        move |(b, _, _)| {
+            if seen.insert(*b) {
+                Some(*b)
+            } else {
+                None
+            }
+        },
+    )
+}

data/src/lib.rs

@@ -1,3 +1,4 @@
+pub mod baseline;
 pub mod caniuse;
 pub mod electron;
 pub mod node;