Shallow clone of https://github.com/wooorm/markdown-rs

tests/test_utils/swc_utils.rs

@@ -0,0 +1,37 @@
+//! Lots of helpers for dealing with SWC, particularly from unist, and for
+//! building its ES AST.
+
+use swc_core::common::{BytePos, Span, DUMMY_SP};
+use swc_core::ecma::visit::{noop_visit_mut_type, VisitMut};
+
+/// Visitor to fix SWC byte positions by removing a prefix.
+///
+/// > 👉 **Note**: SWC byte positions are offset by one: they are `0` when they
+/// > are missing or incremented by `1` when valid.
+#[derive(Debug, Default, Clone)]
+pub struct RewritePrefixContext {
+    /// Size of prefix considered outside this tree.
+    pub prefix_len: u32,
+}
+
+impl VisitMut for RewritePrefixContext {
+    noop_visit_mut_type!();
+
+    /// Rewrite spans.
+    fn visit_mut_span(&mut self, span: &mut Span) {
+        let mut result = DUMMY_SP;
+        if span.lo.0 > self.prefix_len && span.hi.0 > self.prefix_len {
+            result = create_span(span.lo.0 - self.prefix_len, span.hi.0 - self.prefix_len);
+        }
+
+        *span = result;
+    }
+}
+
+/// Generate a span.
+pub fn create_span(lo: u32, hi: u32) -> Span {
+    Span {
+        lo: BytePos(lo),
+        hi: BytePos(hi),
+    }
+}