1 files changed, 142 insertions, 0 deletions
diff --git a/devtools/client/webconsole/components/Input/EagerEvaluation.js b/devtools/client/webconsole/components/Input/EagerEvaluation.js
new file mode 100644
index 0000000000..e70d0ad290
--- /dev/null
+++ b/devtools/client/webconsole/components/Input/EagerEvaluation.js
@@ -0,0 +1,142 @@
+/* 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 { Component } = require("devtools/client/shared/vendor/react");
+const dom = require("devtools/client/shared/vendor/react-dom-factories");
+const { connect } = require("devtools/client/shared/vendor/react-redux");
+
+const {
+  getTerminalEagerResult,
+} = require("devtools/client/webconsole/selectors/history");
+
+const actions = require("devtools/client/webconsole/actions/index");
+
+loader.lazyGetter(this, "REPS", function() {
+  return require("devtools/client/shared/components/reps/index").REPS;
+});
+loader.lazyGetter(this, "MODE", function() {
+  return require("devtools/client/shared/components/reps/index").MODE;
+});
+loader.lazyRequireGetter(
+  this,
+  "PropTypes",
+  "devtools/client/shared/vendor/react-prop-types"
+);
+
+/**
+ * Show the results of evaluating the current terminal text, if possible.
+ */
+class EagerEvaluation extends Component {
+  static get propTypes() {
+    return {
+      terminalEagerResult: PropTypes.any,
+      serviceContainer: PropTypes.object.isRequired,
+      highlightDomElement: PropTypes.func.isRequired,
+      unHighlightDomElement: PropTypes.func.isRequired,
+    };
+  }
+
+  static getDerivedStateFromError(error) {
+    return { hasError: true };
+  }
+
+  componentDidUpdate(prevProps) {
+    const {
+      highlightDomElement,
+      unHighlightDomElement,
+      terminalEagerResult,
+    } = this.props;
+
+    if (canHighlightObject(prevProps.terminalEagerResult)) {
+      unHighlightDomElement(prevProps.terminalEagerResult.getGrip());
+    }
+
+    if (canHighlightObject(terminalEagerResult)) {
+      highlightDomElement(terminalEagerResult.getGrip());
+    }
+
+    if (this.state?.hasError) {
+      // If the render function threw at some point, clear the error after 1s so the
+      // component has a chance to render again.
+      // This way, we don't block instant evaluation for the whole session, in case the
+      // input changed in the meantime. If the input didn't change, we'll hit
+      // getDerivatedStateFromError again (and this won't render anything), so it's safe.
+      setTimeout(() => {
+        this.setState({ hasError: false });
+      }, 1000);
+    }
+  }
+
+  componentWillUnmount() {
+    const { unHighlightDomElement, terminalEagerResult } = this.props;
+
+    if (canHighlightObject(terminalEagerResult)) {
+      unHighlightDomElement(terminalEagerResult.getGrip());
+    }
+  }
+
+  renderRepsResult() {
+    const { terminalEagerResult } = this.props;
+
+    const result = terminalEagerResult.getGrip
+      ? terminalEagerResult.getGrip()
+      : terminalEagerResult;
+    const { isError } = result || {};
+
+    return REPS.Rep({
+      key: "rep",
+      object: result,
+      mode: isError ? MODE.SHORT : MODE.LONG,
+    });
+  }
+
+  render() {
+    const hasResult =
+      this.props.terminalEagerResult !== null && !this.state?.hasError;
+
+    return dom.div(
+      { className: "eager-evaluation-result", key: "eager-evaluation-result" },
+      hasResult
+        ? dom.span(
+            { className: "eager-evaluation-result__row" },
+            dom.span({
+              className: "eager-evaluation-result__icon",
+              key: "icon",
+            }),
+            dom.span(
+              { className: "eager-evaluation-result__text", key: "text" },
+              this.renderRepsResult()
+            )
+          )
+        : null
+    );
+  }
+}
+
+function canHighlightObject(obj) {
+  const grip = obj?.getGrip && obj.getGrip();
+  return (
+    grip &&
+    (REPS.ElementNode.supportsObject(grip) ||
+      REPS.TextNode.supportsObject(grip)) &&
+    grip.preview.isConnected
+  );
+}
+
+function mapStateToProps(state) {
+  return {
+    terminalEagerResult: getTerminalEagerResult(state),
+  };
+}
+
+function mapDispatchToProps(dispatch) {
+  return {
+    highlightDomElement: grip => dispatch(actions.highlightDomElement(grip)),
+    unHighlightDomElement: grip =>
+      dispatch(actions.unHighlightDomElement(grip)),
+  };
+}
+module.exports = connect(mapStateToProps, mapDispatchToProps)(EagerEvaluation);