1 files changed, 117 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/utils/pause/mapScopes/rangeMetadata.js b/devtools/client/debugger/src/utils/pause/mapScopes/rangeMetadata.js
new file mode 100644
index 0000000000..7a22313aca
--- /dev/null
+++ b/devtools/client/debugger/src/utils/pause/mapScopes/rangeMetadata.js
@@ -0,0 +1,117 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */
+
+import { locColumn } from "./locColumn";
+import { positionCmp } from "./positionCmp";
+import { filterSortedArray } from "./filtering";
+
+// * match - Range contains a single identifier with matching start location
+// * contains - Range contains a single identifier with non-matching start
+// * multiple - Range contains multiple identifiers
+// * empty - Range contains no identifiers
+
+export async function loadRangeMetadata(
+  location,
+  originalAstScopes,
+  { sourceMapLoader }
+) {
+  const originalRanges = await sourceMapLoader.getOriginalRanges(
+    location.sourceId
+  );
+
+  const sortedOriginalAstBindings = [];
+  for (const item of originalAstScopes) {
+    for (const name of Object.keys(item.bindings)) {
+      for (const ref of item.bindings[name].refs) {
+        sortedOriginalAstBindings.push(ref);
+      }
+    }
+  }
+  sortedOriginalAstBindings.sort((a, b) => positionCmp(a.start, b.start));
+
+  let i = 0;
+
+  return originalRanges.map(range => {
+    const bindings = [];
+
+    while (
+      i < sortedOriginalAstBindings.length &&
+      (sortedOriginalAstBindings[i].start.line < range.line ||
+        (sortedOriginalAstBindings[i].start.line === range.line &&
+          locColumn(sortedOriginalAstBindings[i].start) < range.columnStart))
+    ) {
+      i++;
+    }
+
+    while (
+      i < sortedOriginalAstBindings.length &&
+      sortedOriginalAstBindings[i].start.line === range.line &&
+      locColumn(sortedOriginalAstBindings[i].start) >= range.columnStart &&
+      locColumn(sortedOriginalAstBindings[i].start) < range.columnEnd
+    ) {
+      const lastBinding = bindings[bindings.length - 1];
+      // Only add bindings when they're in new positions
+      if (
+        !lastBinding ||
+        positionCmp(lastBinding.start, sortedOriginalAstBindings[i].start) !== 0
+      ) {
+        bindings.push(sortedOriginalAstBindings[i]);
+      }
+      i++;
+    }
+
+    let type = "empty";
+    let singleDeclaration = true;
+    if (bindings.length === 1) {
+      const binding = bindings[0];
+      if (
+        binding.start.line === range.line &&
+        binding.start.column === range.columnStart
+      ) {
+        type = "match";
+      } else {
+        type = "contains";
+      }
+    } else if (bindings.length > 1) {
+      type = "multiple";
+      const binding = bindings[0];
+      const declStart =
+        binding.type !== "ref" ? binding.declaration.start : null;
+
+      singleDeclaration = bindings.every(b => {
+        return (
+          declStart &&
+          b.type !== "ref" &&
+          positionCmp(declStart, b.declaration.start) === 0
+        );
+      });
+    }
+
+    return {
+      type,
+      singleDeclaration,
+      ...range,
+    };
+  });
+}
+
+export function findMatchingRange(sortedOriginalRanges, bindingRange) {
+  return filterSortedArray(sortedOriginalRanges, range => {
+    if (range.line < bindingRange.start.line) {
+      return -1;
+    }
+    if (range.line > bindingRange.start.line) {
+      return 1;
+    }
+
+    if (range.columnEnd <= locColumn(bindingRange.start)) {
+      return -1;
+    }
+    if (range.columnStart > locColumn(bindingRange.start)) {
+      return 1;
+    }
+
+    return 0;
+  }).pop();
+}