1 files changed, 244 insertions, 0 deletions
diff --git a/devtools/client/webconsole/reducers/history.js b/devtools/client/webconsole/reducers/history.js
new file mode 100644
index 0000000000..adfca885c5
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+++ b/devtools/client/webconsole/reducers/history.js
@@ -0,0 +1,244 @@
+/* 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 {
+  APPEND_TO_HISTORY,
+  CLEAR_HISTORY,
+  EVALUATE_EXPRESSION,
+  HISTORY_LOADED,
+  UPDATE_HISTORY_POSITION,
+  HISTORY_BACK,
+  HISTORY_FORWARD,
+  REVERSE_SEARCH_INPUT_TOGGLE,
+  REVERSE_SEARCH_INPUT_CHANGE,
+  REVERSE_SEARCH_BACK,
+  REVERSE_SEARCH_NEXT,
+  SET_TERMINAL_INPUT,
+  SET_TERMINAL_EAGER_RESULT,
+} = require("resource://devtools/client/webconsole/constants.js");
+
+/**
+ * Create default initial state for this reducer.
+ */
+function getInitialState() {
+  return {
+    // Array with history entries
+    entries: [],
+
+    // Holds position (index) in history entries that the user is
+    // currently viewing. This is reset to this.entries.length when
+    // APPEND_TO_HISTORY action is fired.
+    position: undefined,
+
+    // Backups the original user value (if any) that can be set in
+    // the input field. It might be used again if the user doesn't
+    // pick up anything from the history and wants to return all
+    // the way back to see the original input text.
+    originalUserValue: null,
+
+    reverseSearchEnabled: false,
+    currentReverseSearchResults: null,
+    currentReverseSearchResultsPosition: null,
+
+    terminalInput: null,
+    terminalEagerResult: null,
+  };
+}
+
+function history(state = getInitialState(), action, prefsState) {
+  switch (action.type) {
+    case APPEND_TO_HISTORY:
+    case EVALUATE_EXPRESSION:
+      return appendToHistory(state, prefsState, action.expression);
+    case CLEAR_HISTORY:
+      return clearHistory(state);
+    case HISTORY_LOADED:
+      return historyLoaded(state, action.entries);
+    case UPDATE_HISTORY_POSITION:
+      return updateHistoryPosition(state, action.direction, action.expression);
+    case REVERSE_SEARCH_INPUT_TOGGLE:
+      return reverseSearchInputToggle(state, action);
+    case REVERSE_SEARCH_INPUT_CHANGE:
+      return reverseSearchInputChange(state, action.value);
+    case REVERSE_SEARCH_BACK:
+      return reverseSearchBack(state);
+    case REVERSE_SEARCH_NEXT:
+      return reverseSearchNext(state);
+    case SET_TERMINAL_INPUT:
+      return setTerminalInput(state, action.expression);
+    case SET_TERMINAL_EAGER_RESULT:
+      return setTerminalEagerResult(state, action.result);
+  }
+  return state;
+}
+
+function appendToHistory(state, prefsState, expression) {
+  // Clone state
+  state = { ...state };
+  state.entries = [...state.entries];
+
+  // Append new expression only if it isn't the same as
+  // the one recently added.
+  if (expression.trim() != state.entries[state.entries.length - 1]) {
+    state.entries.push(expression);
+  }
+
+  // Remove entries if the limit is reached
+  if (state.entries.length > prefsState.historyCount) {
+    state.entries.splice(0, state.entries.length - prefsState.historyCount);
+  }
+
+  state.position = state.entries.length;
+  state.originalUserValue = null;
+
+  return state;
+}
+
+function clearHistory(state) {
+  return getInitialState();
+}
+
+/**
+ * Handling HISTORY_LOADED action that is fired when history
+ * entries created in previous Firefox session are loaded
+ * from async-storage.
+ *
+ * Loaded entries are appended before the ones that were
+ * added to the state in this session.
+ */
+function historyLoaded(state, entries) {
+  const newEntries = [...entries, ...state.entries];
+  return {
+    ...state,
+    entries: newEntries,
+    // Default position is at the end of the list
+    // (at the latest inserted item).
+    position: newEntries.length,
+    originalUserValue: null,
+  };
+}
+
+function updateHistoryPosition(state, direction, expression) {
+  // Handle UP arrow key => HISTORY_BACK
+  // Handle DOWN arrow key => HISTORY_FORWARD
+  if (direction == HISTORY_BACK) {
+    if (state.position <= 0) {
+      return state;
+    }
+
+    // Clone state
+    state = { ...state };
+
+    // Store the current input value when the user starts
+    // browsing through the history.
+    if (state.position == state.entries.length) {
+      state.originalUserValue = expression || "";
+    }
+
+    state.position--;
+  } else if (direction == HISTORY_FORWARD) {
+    if (state.position >= state.entries.length) {
+      return state;
+    }
+
+    state = {
+      ...state,
+      position: state.position + 1,
+    };
+  }
+
+  return state;
+}
+
+function reverseSearchInputToggle(state, action) {
+  const { initialValue = "" } = action;
+
+  // We're going to close the reverse search, let's clean the state
+  if (state.reverseSearchEnabled) {
+    return {
+      ...state,
+      reverseSearchEnabled: false,
+      position: undefined,
+      currentReverseSearchResults: null,
+      currentReverseSearchResultsPosition: null,
+    };
+  }
+
+  // If we're enabling the reverse search, we treat it as a reverse search input change,
+  // since we can have an initial value.
+  return reverseSearchInputChange(state, initialValue);
+}
+
+function reverseSearchInputChange(state, searchString) {
+  if (searchString === "") {
+    return {
+      ...state,
+      position: undefined,
+      currentReverseSearchResults: null,
+      currentReverseSearchResultsPosition: null,
+    };
+  }
+
+  searchString = searchString.toLocaleLowerCase();
+  const matchingEntries = state.entries.filter(entry =>
+    entry.toLocaleLowerCase().includes(searchString)
+  );
+  // We only return unique entries, but we want to keep the latest entry in the array if
+  // it's duplicated (e.g. if we have [1,2,1], we want to get [2,1], not [1,2]).
+  // To do that, we need to reverse the matching entries array, provide it to a Set,
+  // transform it back to an array and reverse it again.
+  const uniqueEntries = new Set(matchingEntries.reverse());
+  const currentReverseSearchResults = Array.from(
+    new Set(uniqueEntries)
+  ).reverse();
+
+  return {
+    ...state,
+    position: undefined,
+    currentReverseSearchResults,
+    currentReverseSearchResultsPosition: currentReverseSearchResults.length - 1,
+  };
+}
+
+function reverseSearchBack(state) {
+  let nextPosition = state.currentReverseSearchResultsPosition - 1;
+  if (nextPosition < 0) {
+    nextPosition = state.currentReverseSearchResults.length - 1;
+  }
+
+  return {
+    ...state,
+    currentReverseSearchResultsPosition: nextPosition,
+  };
+}
+
+function reverseSearchNext(state) {
+  let previousPosition = state.currentReverseSearchResultsPosition + 1;
+  if (previousPosition >= state.currentReverseSearchResults.length) {
+    previousPosition = 0;
+  }
+
+  return {
+    ...state,
+    currentReverseSearchResultsPosition: previousPosition,
+  };
+}
+
+function setTerminalInput(state, expression) {
+  return {
+    ...state,
+    terminalInput: expression,
+    terminalEagerResult: !expression ? null : state.terminalEagerResult,
+  };
+}
+
+function setTerminalEagerResult(state, result) {
+  return {
+    ...state,
+    terminalEagerResult: result,
+  };
+}
+
+exports.history = history;