fix: stabilize streaming footer and status layout (#882)

vendor/ink/build/log-update.js

@@ -0,0 +1,63 @@
+import ansiEscapes from 'ansi-escapes';
+import cliCursor from 'cli-cursor';
+
+const create = (stream, { showCursor = false } = {}) => {
+    let previousLineCount = 0;
+    let previousOutput = '';
+    let hasHiddenCursor = false;
+
+    const renderWithClearedLineEnds = (output) => {
+        const lines = output.split('\n');
+        return lines.map((line) => line + ansiEscapes.eraseEndLine).join('\n');
+    };
+
+    const render = (str) => {
+        if (!showCursor && !hasHiddenCursor) {
+            cliCursor.hide();
+            hasHiddenCursor = true;
+        }
+
+        const output = str + '\n';
+        if (output === previousOutput) {
+            return;
+        }
+
+        // Keep existing line-count semantics used by Ink's bundled log-update.
+        const nextLineCount = output.split('\n').length;
+
+        // Avoid eraseLines() pre-clear flashes by repainting in place:
+        // move to start of previous frame, rewrite each line while erasing EOL,
+        // then clear any trailing old lines if the frame got shorter.
+        if (previousLineCount > 1) {
+            stream.write(ansiEscapes.cursorUp(previousLineCount - 1));
+        }
+        stream.write(renderWithClearedLineEnds(output));
+        if (nextLineCount < previousLineCount) {
+            stream.write(ansiEscapes.eraseDown);
+        }
+
+        previousOutput = output;
+        previousLineCount = nextLineCount;
+    };
+
+    render.clear = () => {
+        stream.write(ansiEscapes.eraseLines(previousLineCount));
+        previousOutput = '';
+        previousLineCount = 0;
+    };
+
+    render.done = () => {
+        previousOutput = '';
+        previousLineCount = 0;
+        if (!showCursor) {
+            cliCursor.show();
+            hasHiddenCursor = false;
+        }
+    };
+
+    return render;
+};
+
+const logUpdate = { create };
+export default logUpdate;
+