textDocument/selectionRange

closes #777

tests/lsp_features/selection_range.zig

@@ -0,0 +1,76 @@
+const std = @import("std");
+const zls = @import("zls");
+const builtin = @import("builtin");
+
+const helper = @import("../helper.zig");
+const Context = @import("../context.zig").Context;
+const ErrorBuilder = @import("../ErrorBuilder.zig");
+
+const types = zls.types;
+const offsets = zls.offsets;
+const requests = zls.requests;
+
+const allocator: std.mem.Allocator = std.testing.allocator;
+
+test "selectionRange - empty" {
+    try testSelectionRange("<>", &.{});
+}
+
+test "seletionRange - smoke" {
+    try testSelectionRange(
+        \\fn main() void {
+        \\    const x = 1 <>+ 1;
+        \\}
+    , &.{ "1 + 1", "const x = 1 + 1", "{\n    const x = 1 + 1;\n}" });
+}
+
+fn testSelectionRange(source: []const u8, want: []const []const u8) !void {
+    var phr = try helper.collectClearPlaceholders(allocator, source);
+    defer phr.deinit(allocator);
+
+    var ctx = try Context.init();
+    defer ctx.deinit();
+
+    const test_uri: []const u8 = switch (builtin.os.tag) {
+        .windows => "file:///C:\\test.zig",
+        else => "file:///test.zig",
+    };
+
+    try ctx.requestDidOpen(test_uri, phr.new_source);
+
+    const position = offsets.locToRange(phr.new_source, phr.locations.items(.new)[0], .utf16).start;
+
+    const SelectionRange = struct {
+        range: types.Range,
+        parent: ?*@This(),
+    };
+
+    const request = requests.SelectionRange{ .params = .{
+        .textDocument = .{ .uri = test_uri },
+        .positions = &.{position},
+    } };
+
+    const response = try ctx.requestGetResponse(?[]SelectionRange, "textDocument/selectionRange", request);
+    defer response.deinit();
+
+    const selectionRanges: []SelectionRange = response.result orelse {
+        std.debug.print("Server returned `null` as the result\n", .{});
+        return error.InvalidResponse;
+    };
+
+    var got = std.ArrayList([]const u8).init(allocator);
+    defer got.deinit();
+
+    var it: ?*SelectionRange = &selectionRanges[0];
+    while (it) |r| {
+        const slice = offsets.rangeToSlice(phr.new_source, r.range, .utf16);
+        (try got.addOne()).* = slice;
+        it = r.parent;
+    }
+    const last = got.pop();
+    try std.testing.expectEqualStrings(phr.new_source, last);
+    try std.testing.expectEqual(want.len, got.items.len);
+    for (want) |w, i| {
+        try std.testing.expectEqualStrings(w, got.items[i]);
+    }
+}

tests/tests.zig

@@ -14,6 +14,7 @@ comptime {
     _ = @import("lsp_features/inlay_hints.zig");
     _ = @import("lsp_features/references.zig");
     _ = @import("lsp_features/completion.zig");
+    _ = @import("lsp_features/selection_range.zig");
 
     // Language features
     _ = @import("language_features/cimport.zig");