1 files changed, 211 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..992737e2d1
--- /dev/null
+++ b/devtools/client/debugger/src/actions/preview.js
@@ -0,0 +1,211 @@
+/* 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 { isConsole } from "../utils/preview";
+import { findBestMatchExpression } from "../utils/ast";
+import { getGrip, getFront } from "../utils/evaluation-result";
+import { getExpressionFromCoords } from "../utils/editor/get-expression";
+import { isNodeTest } from "../utils/environment";
+
+import {
+  getPreview,
+  isLineInScope,
+  isSelectedFrameVisible,
+  getSelectedSource,
+  getSelectedLocation,
+  getSelectedFrame,
+  getSymbols,
+  getCurrentThread,
+  getPreviewCount,
+  getSelectedException,
+} from "../selectors";
+
+import { getMappedExpression } from "./expressions";
+
+function findExpressionMatch(state, codeMirror, tokenPos) {
+  const location = getSelectedLocation(state);
+  if (!location) {
+    return null;
+  }
+
+  const symbols = getSymbols(state, location);
+
+  let match;
+  if (!symbols) {
+    match = getExpressionFromCoords(codeMirror, tokenPos);
+  } else {
+    match = findBestMatchExpression(symbols, tokenPos);
+  }
+  return match;
+}
+
+export function updatePreview(cx, target, tokenPos, codeMirror) {
+  return ({ dispatch, getState }) => {
+    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,
+  expression,
+  location,
+  tokenPos,
+  cursorPos,
+  target
+) {
+  return async ({ dispatch, getState, client }) => {
+    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 && source.isOriginal) {
+      const mapResult = await dispatch(getMappedExpression(expression));
+      if (mapResult) {
+        expression = mapResult.expression;
+      }
+    }
+
+    if (!selectedFrame) {
+      return;
+    }
+
+    const { result } = await client.evaluate(expression, {
+      frameId: selectedFrame.id,
+    });
+
+    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 = {
+      path: expression,
+      contents: {
+        value: resultGrip,
+        front: getFront(result),
+      },
+    };
+    const properties = await client.loadObjectProperties(root, thread);
+
+    // 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) {
+  return ({ dispatch, getState, client }) => {
+    const currentSelection = getPreview(getState());
+    if (!currentSelection) {
+      return null;
+    }
+
+    return dispatch({
+      type: "CLEAR_PREVIEW",
+      cx,
+    });
+  };
+}
+
+export function setExceptionPreview(cx, target, tokenPos, codeMirror) {
+  return async ({ dispatch, getState }) => {
+    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,
+      },
+    });
+  };
+}