1 files changed, 95 insertions, 0 deletions
diff --git a/devtools/client/webconsole/selectors/history.js b/devtools/client/webconsole/selectors/history.js
new file mode 100644
index 0000000000..531db8b8a8
--- /dev/null
+++ b/devtools/client/webconsole/selectors/history.js
@@ -0,0 +1,95 @@
+/* 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/. */
+
+"use strict";
+
+const {
+  HISTORY_BACK,
+  HISTORY_FORWARD,
+} = require("resource://devtools/client/webconsole/constants.js");
+
+function getHistory(state) {
+  return state.history;
+}
+
+function getHistoryEntries(state) {
+  return state.history.entries;
+}
+
+function getHistoryValue(state, direction) {
+  if (direction == HISTORY_BACK) {
+    return getPreviousHistoryValue(state);
+  }
+  if (direction == HISTORY_FORWARD) {
+    return getNextHistoryValue(state);
+  }
+  return null;
+}
+
+function getNextHistoryValue(state) {
+  if (state.history.position < state.history.entries.length - 1) {
+    return state.history.entries[state.history.position + 1];
+  }
+
+  // The user didn't pick up anything from the history and returned
+  // back to the previous value (if any) that was in the input box.
+  return state.history.originalUserValue;
+}
+
+function getPreviousHistoryValue(state) {
+  if (state.history.position > 0) {
+    return state.history.entries[state.history.position - 1];
+  }
+  return null;
+}
+
+function getReverseSearchResult(state) {
+  const { history } = state;
+  const { currentReverseSearchResults, currentReverseSearchResultsPosition } =
+    history;
+
+  if (
+    !Array.isArray(currentReverseSearchResults) ||
+    currentReverseSearchResults.length === 0 ||
+    !Number.isInteger(currentReverseSearchResultsPosition)
+  ) {
+    return null;
+  }
+  return currentReverseSearchResults[currentReverseSearchResultsPosition];
+}
+
+function getReverseSearchResultPosition(state) {
+  const { history } = state;
+  const { currentReverseSearchResultsPosition } = history;
+  if (!Number.isInteger(currentReverseSearchResultsPosition)) {
+    return currentReverseSearchResultsPosition;
+  }
+
+  return currentReverseSearchResultsPosition + 1;
+}
+
+function getReverseSearchTotalResults(state) {
+  const { history } = state;
+  const { currentReverseSearchResults } = history;
+  if (!currentReverseSearchResults) {
+    return null;
+  }
+
+  return currentReverseSearchResults.length;
+}
+
+function getTerminalEagerResult(state) {
+  const { history } = state;
+  return history.terminalEagerResult;
+}
+
+module.exports = {
+  getHistory,
+  getHistoryEntries,
+  getHistoryValue,
+  getReverseSearchResult,
+  getReverseSearchResultPosition,
+  getReverseSearchTotalResults,
+  getTerminalEagerResult,
+};