1 files changed, 121 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/selectors/breakpointAtLocation.js b/devtools/client/debugger/src/selectors/breakpointAtLocation.js
new file mode 100644
index 0000000000..c661894dbb
--- /dev/null
+++ b/devtools/client/debugger/src/selectors/breakpointAtLocation.js
@@ -0,0 +1,121 @@
+/* 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 { getSelectedSource, getBreakpointPositionsForLine } from "./sources";
+import { getBreakpointsList } from "./breakpoints";
+import { isGenerated } from "../utils/source";
+
+function getColumn(column, selectedSource) {
+  if (column) {
+    return column;
+  }
+
+  return isGenerated(selectedSource) ? undefined : 0;
+}
+
+function getLocation(bp, selectedSource) {
+  return isGenerated(selectedSource)
+    ? bp.generatedLocation || bp.location
+    : bp.location;
+}
+
+function getBreakpointsForSource(state, selectedSource) {
+  const breakpoints = getBreakpointsList(state);
+
+  return breakpoints.filter(bp => {
+    const location = getLocation(bp, selectedSource);
+    return location.sourceId === selectedSource.id;
+  });
+}
+
+function findBreakpointAtLocation(
+  breakpoints,
+  selectedSource,
+  { line, column }
+) {
+  return breakpoints.find(breakpoint => {
+    const location = getLocation(breakpoint, selectedSource);
+    const sameLine = location.line === line;
+    if (!sameLine) {
+      return false;
+    }
+
+    if (column === undefined) {
+      return true;
+    }
+
+    return location.column === getColumn(column, selectedSource);
+  });
+}
+
+// returns the closest active column breakpoint
+function findClosestBreakpoint(breakpoints, column) {
+  if (!breakpoints || !breakpoints.length) {
+    return null;
+  }
+
+  const firstBreakpoint = breakpoints[0];
+  return breakpoints.reduce((closestBp, currentBp) => {
+    const currentColumn = currentBp.generatedLocation.column;
+    const closestColumn = closestBp.generatedLocation.column;
+    // check that breakpoint has a column.
+    if (column && currentColumn && closestColumn) {
+      const currentDistance = Math.abs(currentColumn - column);
+      const closestDistance = Math.abs(closestColumn - column);
+
+      return currentDistance < closestDistance ? currentBp : closestBp;
+    }
+    return closestBp;
+  }, firstBreakpoint);
+}
+
+/*
+ * Finds a breakpoint at a location (line, column) of the
+ * selected source.
+ *
+ * This is useful for finding a breakpoint when the
+ * user clicks in the gutter or on a token.
+ */
+export function getBreakpointAtLocation(state, location) {
+  const selectedSource = getSelectedSource(state);
+  if (!selectedSource) {
+    throw new Error("no selectedSource");
+  }
+  const breakpoints = getBreakpointsForSource(state, selectedSource);
+
+  return findBreakpointAtLocation(breakpoints, selectedSource, location);
+}
+
+export function getBreakpointsAtLine(state, line) {
+  const selectedSource = getSelectedSource(state);
+  if (!selectedSource) {
+    throw new Error("no selectedSource");
+  }
+  const breakpoints = getBreakpointsForSource(state, selectedSource);
+
+  return breakpoints.filter(
+    breakpoint => getLocation(breakpoint, selectedSource).line === line
+  );
+}
+
+export function getClosestBreakpoint(state, position) {
+  const columnBreakpoints = getBreakpointsAtLine(state, position.line);
+  const breakpoint = findClosestBreakpoint(columnBreakpoints, position.column);
+  return breakpoint;
+}
+
+export function getClosestBreakpointPosition(state, position) {
+  const selectedSource = getSelectedSource(state);
+  if (!selectedSource) {
+    throw new Error("no selectedSource");
+  }
+
+  const columnBreakpoints = getBreakpointPositionsForLine(
+    state,
+    selectedSource.id,
+    position.line
+  );
+
+  return findClosestBreakpoint(columnBreakpoints, position.column);
+}