Make find-and-replace search from the caret's position when opened (Fixes #156)

plugins/find-and-replace.js

@@ -186,7 +186,9 @@ codeInput.plugins.FindAndReplace = class extends codeInput.Plugin {
     }
 
     /**
-     * Show a find-and-replace dialog.
+     * Show a find-and-replace dialog. The first match focused is the first one at or
+     * after the caret's position when this is called, wrapping back round to the start
+     * of the code if there is no such match.
      * @param {codeInput.CodeInput} codeInputElement the `<code-input>` element.
      * @param {boolean} replacePartExpanded whether the replace part of the find-and-replace dialog should be expanded
     */
@@ -412,6 +414,12 @@ codeInput.plugins.FindAndReplace = class extends codeInput.Plugin {
         dialog.selectionStart = codeInputElement.textareaElement.selectionStart;
         dialog.selectionEnd = codeInputElement.textareaElement.selectionEnd;
 
+        // Start searching from the caret's position at the moment the dialog was
+        // opened, like most IDEs do. The findMatchState is only constructed when the
+        // dialog is first created, so without this every reopening of the dialog would
+        // carry on from wherever the previous search left off instead.
+        dialog.findMatchState.focusedMatchStartIndex = dialog.selectionStart;
+
         if(dialog.selectionStart < dialog.selectionEnd) {
             // Copy selected text to Find input
             let textToFind = codeInputElement.textareaElement.value.substring(dialog.selectionStart, dialog.selectionEnd);

tests/tester.js

@@ -761,6 +761,38 @@ console.log("I've got another line!", 2 < 3, "should be true.");
     codeInputElement.querySelector(".code-input_find-and-replace_dialog").dispatchEvent(new KeyboardEvent("keydown", { "key": "Escape" }));
     codeInputElement.querySelector(".code-input_find-and-replace_dialog").dispatchEvent(new KeyboardEvent("keyup", { "key": "Escape" }));
 
+    // Opening the dialog searches from the caret's position at that moment, rather than
+    // carrying on from wherever the previous search left off. In the code above, "hi" is
+    // at indexes 3, 16 and 29.
+    // Open the dialog with the caret at the given index, then close it, which selects the
+    // focused match; returns the index that match starts at.
+    async function findFromCaret(caret) {
+        findInput.value = "hi";
+        textarea.focus();
+        textarea.selectionStart = textarea.selectionEnd = caret;
+        if(navigator.platform.startsWith("Mac") || navigator.platform === "iPhone") {
+            textarea.dispatchEvent(new KeyboardEvent("keydown", { "cancelable": true, "key": "f", "metaKey": true }));
+        } else {
+            textarea.dispatchEvent(new KeyboardEvent("keydown", { "cancelable": true, "key": "f", "ctrlKey": true }));
+        }
+        await waitAsync(250); // Wait for highlighting so matches update
+
+        const dialog = codeInputElement.querySelector(".code-input_find-and-replace_dialog");
+        dialog.dispatchEvent(new KeyboardEvent("keydown", { "key": "Escape" }));
+        dialog.dispatchEvent(new KeyboardEvent("keyup", { "key": "Escape" }));
+        await waitAsync(150); // Wait for the dialog to close and select the focused match
+
+        return textarea.selectionStart;
+    }
+
+    // These two are ordered so the match the previous one left focused differs from the
+    // correct answer, so they fail if the caret's position is ignored.
+    assertEqual("FindAndReplace", "Finds First Match After Caret when Reopened", await findFromCaret(17), 29);
+    assertEqual("FindAndReplace", "Finds Match Starting Exactly at Caret", await findFromCaret(16), 16);
+    // These two lock in the surrounding behaviour, and pass either way.
+    assertEqual("FindAndReplace", "Wraps to First Match when Caret is After Last Match", await findFromCaret(30), 3);
+    assertEqual("FindAndReplace", "Keeps Focused Match when Reopened without Moving Caret", await findFromCaret(3), 3);
+
     // GoToLine
     // Replace all code
     textarea.selectionStart = 0;