Add LSP hover and signature panels

src/tui.zig

@@ -160,6 +160,10 @@ pub const Client = struct {
         if (std.mem.startsWith(u8, line, "lsp_rename ")) return self.openLspWorkspaceEdit("rename", line[11..]);
         if (std.mem.startsWith(u8, line, "lsp_code_actions ")) return self.openLspCodeActions(line[17..]);
         if (std.mem.eql(u8, line, "lsp_edit_apply_selected")) return self.applySelectedLspEdit();
+        if (std.mem.startsWith(u8, line, "lsp_hover ")) return self.openLspHover(line[10..]);
+        if (std.mem.startsWith(u8, line, "lsp_signature ")) return self.openLspSignature(line[14..]);
+        if (std.mem.eql(u8, line, "lsp_param_next")) return self.moveLspParameter(.next);
+        if (std.mem.eql(u8, line, "lsp_param_previous")) return self.moveLspParameter(.previous);
         if (std.mem.startsWith(u8, line, "panel_open ")) return self.applyProtocolCommand(line);
         if (std.mem.startsWith(u8, line, "list_open ")) return self.applyProtocolCommand(line);
         if (std.mem.startsWith(u8, line, "list_filter ")) return self.applyProtocolCommand(line);
@@ -508,6 +512,31 @@ pub const Client = struct {
         self.message = null;
     }
 
+    fn openLspHover(self: *Client, payload: []const u8) !void {
+        const rows = lsp_mod.hoverRowsAlloc(self.allocator, payload, self.viewport.width) catch return Error.ProtocolRejected;
+        defer freeOwnedRows(self.allocator, rows);
+        try self.session.openListPanel("lsp-hover", rows);
+        self.message = null;
+    }
+
+    fn openLspSignature(self: *Client, payload: []const u8) !void {
+        const rows = lsp_mod.signatureRowsAlloc(self.allocator, payload, self.viewport.width) catch return Error.ProtocolRejected;
+        defer freeOwnedRows(self.allocator, rows);
+        try self.session.openListPanel("lsp-signature", rows);
+        self.message = null;
+    }
+
+    fn moveLspParameter(self: *Client, direction: lsp_mod.ParameterDirection) !void {
+        const snap = try self.session.snapshot();
+        const moved = lsp_mod.parameterMoveRowsAlloc(self.allocator, snap.bytes, snap.cursor_byte, direction) catch return Error.ProtocolRejected;
+        defer freeOwnedRows(self.allocator, moved.rows);
+        const bytes = try self.allocator.dupe(u8, snap.bytes);
+        defer self.allocator.free(bytes);
+        try self.session.openFixtureAt(bytes, moved.cursor);
+        try self.session.openListPanel("lsp-parameter", moved.rows);
+        self.message = null;
+    }
+
     fn jumpCurrentBufferToLspLocation(self: *Client, location: lsp_mod.DiagnosticLocation) !void {
         const snap = try self.session.snapshot();
         const bytes = try self.allocator.dupe(u8, snap.bytes);
@@ -1858,3 +1887,70 @@ test "adversarial: lsp edit failures do not corrupt current buffer" {
     const snap = try client.session.snapshot();
     try std.testing.expectEqualStrings("safe", snap.bytes);
 }
+
+test "regular: lsp hover wraps inside narrow viewport" {
+    var client = try Client.init(std.testing.allocator, .{ .width = 32, .height = 7 });
+    defer client.deinit();
+
+    const payload =
+        \\{"jsonrpc":"2.0","id":8,"result":{"contents":{"kind":"markdown","value":"pub fn add(lhs: i32, rhs: i32) i32"}}}
+    ;
+    const command = try std.fmt.allocPrint(std.testing.allocator, "lsp_hover {s}", .{payload});
+    defer std.testing.allocator.free(command);
+    try client.handleTraceLine(command);
+    const frame = try client.render(std.testing.allocator);
+    defer std.testing.allocator.free(frame);
+    try std.testing.expect(std.mem.indexOf(u8, frame, "lsp-hover") != null);
+    try std.testing.expect(std.mem.indexOf(u8, frame, "lsp:hover:") != null);
+    try assertLinesFit(frame, 32);
+}
+
+test "regular: lsp signature shows active parameter in shared panel" {
+    var client = try Client.init(std.testing.allocator, .{ .width = 64, .height = 7 });
+    defer client.deinit();
+
+    const payload =
+        \\{"jsonrpc":"2.0","id":9,"result":{"activeSignature":0,"activeParameter":1,"signatures":[{"label":"add(lhs: i32, rhs: i32)","parameters":[{"label":"lhs: i32"},{"label":"rhs: i32"}]}]}}
+    ;
+    const command = try std.fmt.allocPrint(std.testing.allocator, "lsp_signature {s}", .{payload});
+    defer std.testing.allocator.free(command);
+    try client.handleTraceLine(command);
+    const frame = try client.render(std.testing.allocator);
+    defer std.testing.allocator.free(frame);
+    try std.testing.expect(std.mem.indexOf(u8, frame, "lsp-signature") != null);
+    try std.testing.expect(std.mem.indexOf(u8, frame, "lsp:signature:active_2") != null);
+    try std.testing.expect(std.mem.indexOf(u8, frame, "lsp:signature:param_2:active") != null);
+}
+
+test "regular: lsp parameter movement updates cursor and reports active parameter" {
+    var client = try Client.init(std.testing.allocator, .{ .width = 72, .height = 6 });
+    defer client.deinit();
+
+    try client.session.openFixtureAt("add(alpha, beta, gamma)", 5);
+    try client.handleTraceLine("lsp_param_next");
+    var snap = try client.session.snapshot();
+    try std.testing.expectEqual(@as(usize, 11), snap.cursor_byte);
+    {
+        const frame = try client.render(std.testing.allocator);
+        defer std.testing.allocator.free(frame);
+        try std.testing.expect(std.mem.indexOf(u8, frame, "lsp:param:active_2:11") != null);
+    }
+    try client.handleTraceLine("lsp_param_previous");
+    snap = try client.session.snapshot();
+    try std.testing.expectEqual(@as(usize, 4), snap.cursor_byte);
+}
+
+test "adversarial: malformed hover signature and non-call parameter movement are safe" {
+    var client = try Client.init(std.testing.allocator, .{ .width = 64, .height = 5 });
+    defer client.deinit();
+
+    try client.handleTraceLine("open safe");
+    try std.testing.expectError(Error.ProtocolRejected, client.handleTraceLine("lsp_hover not-json"));
+    try std.testing.expectError(Error.ProtocolRejected, client.handleTraceLine("lsp_signature not-json"));
+    try client.handleTraceLine("lsp_param_next");
+    const snap = try client.session.snapshot();
+    try std.testing.expectEqualStrings("safe", snap.bytes);
+    const frame = try client.render(std.testing.allocator);
+    defer std.testing.allocator.free(frame);
+    try std.testing.expect(std.mem.indexOf(u8, frame, "lsp:param:outside_call") != null);
+}