1 files changed, 231 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/actions/preview.js b/devtools/client/debugger/src/actions/preview.js
new file mode 100644
index 0000000000..b07ae69d1f
--- /dev/null
+++ b/devtools/client/debugger/src/actions/preview.js
@@ -0,0 +1,231 @@
+/* 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/>. */
+
+// @flow
+
+import { isConsole } from "../utils/preview";
+import { findBestMatchExpression } from "../utils/ast";
+import { getGrip, getFront } from "../utils/evaluation-result";
+import { getExpressionFromCoords } from "../utils/editor/get-expression";
+import { isOriginal } from "../utils/source";
+import { isNodeTest } from "../utils/environment";
+
+import {
+  getPreview,
+  isLineInScope,
+  isSelectedFrameVisible,
+  getSelectedSource,
+  getSelectedFrame,
+  getSymbols,
+  getCurrentThread,
+  getPreviewCount,
+  getSelectedException,
+} from "../selectors";
+
+import { getMappedExpression } from "./expressions";
+
+import type { Action, ThunkArgs } from "./types";
+import type { Position, Context } from "../types";
+import type { AstLocation } from "../workers/parser";
+
+function findExpressionMatch(state, codeMirror: any, tokenPos: Object) {
+  const source = getSelectedSource(state);
+  if (!source) {
+    return;
+  }
+
+  const symbols = getSymbols(state, source);
+
+  let match;
+  if (!symbols || symbols.loading) {
+    match = getExpressionFromCoords(codeMirror, tokenPos);
+  } else {
+    match = findBestMatchExpression(symbols, tokenPos);
+  }
+  return match;
+}
+
+export function updatePreview(
+  cx: Context,
+  target: HTMLElement,
+  tokenPos: Object,
+  codeMirror: any
+) {
+  return ({ dispatch, getState, client, sourceMaps }: ThunkArgs) => {
+    const cursorPos = target.getBoundingClientRect();
+
+    if (
+      !isSelectedFrameVisible(getState()) ||
+      !isLineInScope(getState(), tokenPos.line)
+    ) {
+      return;
+    }
+
+    const match = findExpressionMatch(getState(), codeMirror, tokenPos);
+    if (!match) {
+      return;
+    }
+
+    const { expression, location } = match;
+
+    if (isConsole(expression)) {
+      return;
+    }
+
+    dispatch(setPreview(cx, expression, location, tokenPos, cursorPos, target));
+  };
+}
+
+export function setPreview(
+  cx: Context,
+  expression: string,
+  location: AstLocation,
+  tokenPos: Position,
+  cursorPos: ClientRect,
+  target: HTMLElement
+) {
+  return async ({ dispatch, getState, client, sourceMaps }: ThunkArgs) => {
+    dispatch({ type: "START_PREVIEW" });
+    const previewCount = getPreviewCount(getState());
+    if (getPreview(getState())) {
+      dispatch(clearPreview(cx));
+    }
+
+    const source = getSelectedSource(getState());
+    if (!source) {
+      return;
+    }
+
+    const thread = getCurrentThread(getState());
+    const selectedFrame = getSelectedFrame(getState(), thread);
+
+    if (location && isOriginal(source)) {
+      const mapResult = await dispatch(getMappedExpression(expression));
+      if (mapResult) {
+        expression = mapResult.expression;
+      }
+    }
+
+    if (!selectedFrame) {
+      return;
+    }
+
+    const { result } = await client.evaluateInFrame(expression, {
+      frameId: selectedFrame.id,
+      thread,
+    });
+
+    const resultGrip = getGrip(result);
+
+    // Error case occurs for a token that follows an errored evaluation
+    // https://github.com/firefox-devtools/debugger/pull/8056
+    // Accommodating for null allows us to show preview for falsy values
+    // line "", false, null, Nan, and more
+    if (resultGrip === null) {
+      return;
+    }
+
+    // Handle cases where the result is invisible to the debugger
+    // and not possible to preview. Bug 1548256
+    if (
+      resultGrip &&
+      resultGrip.class &&
+      typeof resultGrip.class === "string" &&
+      resultGrip.class.includes("InvisibleToDebugger")
+    ) {
+      return;
+    }
+
+    const root = {
+      name: expression,
+      path: expression,
+      contents: {
+        value: resultGrip,
+        front: getFront(result),
+      },
+    };
+    const properties = await client.loadObjectProperties(root);
+
+    // The first time a popup is rendered, the mouse should be hovered
+    // on the token. If it happens to be hovered on whitespace, it should
+    // not render anything
+    if (!target.matches(":hover") && !isNodeTest()) {
+      return;
+    }
+
+    // Don't finish dispatching if another setPreview was started
+    if (previewCount != getPreviewCount(getState())) {
+      return;
+    }
+
+    dispatch({
+      type: "SET_PREVIEW",
+      cx,
+      value: {
+        expression,
+        resultGrip,
+        properties,
+        root,
+        location,
+        tokenPos,
+        cursorPos,
+        target,
+      },
+    });
+  };
+}
+
+export function clearPreview(cx: Context) {
+  return ({ dispatch, getState, client }: ThunkArgs) => {
+    const currentSelection = getPreview(getState());
+    if (!currentSelection) {
+      return;
+    }
+
+    return dispatch(
+      ({
+        type: "CLEAR_PREVIEW",
+        cx,
+      }: Action)
+    );
+  };
+}
+
+export function setExceptionPreview(
+  cx: Context,
+  target: HTMLElement,
+  tokenPos: Object,
+  codeMirror: any
+) {
+  return async ({ dispatch, getState }: ThunkArgs) => {
+    const cursorPos = target.getBoundingClientRect();
+
+    const match = findExpressionMatch(getState(), codeMirror, tokenPos);
+    if (!match) {
+      return;
+    }
+
+    const tokenColumnStart = match.location.start.column + 1;
+    const exception = getSelectedException(
+      getState(),
+      tokenPos.line,
+      tokenColumnStart
+    );
+    if (!exception) {
+      return;
+    }
+
+    dispatch({
+      type: "SET_PREVIEW",
+      cx,
+      value: {
+        exception,
+        location: match.location,
+        tokenPos,
+        cursorPos,
+        target,
+      },
+    });
+  };
+}