diff --git a/tests/testthat/test-render.R b/tests/testthat/test-render.R
index dfb6c35..045a7dc 100644
--- a/tests/testthat/test-render.R
+++ b/tests/testthat/test-render.R
@@ -50,3 +50,31 @@ test_that("reactlog_widget() inlines the page and defaults to shiny::reactlog()"
   # no line breaks inside the base64 data uris
   expect_false(grepl("base64,[A-Za-z0-9+/=]*\n", html))
 })
+
+test_that("reactlog_render() fills the template and copies the assets", {
+  file <- reactlog_render(structure(list(), version = "1"), time = FALSE)
+  html <- paste(readLines(file, warn = FALSE), collapse = "\n")
+
+  expect_false(grepl("__DATA__", html, fixed = TRUE))
+  expect_false(grepl("defaultLog.js", html, fixed = TRUE))
+  expect_true(grepl("window.__APP_TIME__ = String(\"FALSE\")", html, fixed = TRUE))
+  expect_true(file.exists(file.path(dirname(file), "reactlogAsset", "reactlog.js")))
+})
+
+test_that("reactlog_widget() passes `time`, `session_token`, and sizes on", {
+  skip_if_not_installed("htmlwidgets")
+  log <- structure(list(
+    list(action = "define", reactId = "r1", label = "label_session_a", session = "a"),
+    list(action = "define", reactId = "r2", label = "label_session_b", session = "b")
+  ), version = "1")
+  w <- reactlog_widget(
+    log, time = FALSE, session_token = "a",
+    width = 300, height = 200, elementId = "my_log"
+  )
+
+  expect_true(grepl("String(\"FALSE\")", w$x$html, fixed = TRUE))
+  expect_true(grepl("label_session_a", w$x$html, fixed = TRUE))
+  expect_false(grepl("label_session_b", w$x$html, fixed = TRUE))
+  expect_equal(c(w$width, w$height), c(300, 200))
+  expect_equal(w$elementId, "my_log")
+})
diff --git a/tests/testthat/test-setReactLog.R b/tests/testthat/test-setReactLog.R
new file mode 100644
index 0000000..2756928
--- /dev/null
+++ b/tests/testthat/test-setReactLog.R
@@ -0,0 +1,7 @@
+test_that("reactlog_enable() and reactlog_disable() set the shiny option", {
+  withr::local_options(shiny.reactlog = NULL)
+  reactlog_enable()
+  expect_true(getOption("shiny.reactlog"))
+  reactlog_disable(warn = FALSE)
+  expect_false(getOption("shiny.reactlog"))
+})
diff --git a/tests/testthat/test-shiny_module.R b/tests/testthat/test-shiny_module.R
index 98c6726..734b389 100644
--- a/tests/testthat/test-shiny_module.R
+++ b/tests/testthat/test-shiny_module.R
@@ -22,6 +22,8 @@ test_that("iframe is displayed immediately", {
     testthat::skip(paste0("Insufficient shiny version. Need >= ", shiny_version_required()))
   }
 
+  # testServer() calls require(shiny); attach it first so nothing is printed
+  withr::local_package("shiny")
   shiny::testServer(
     reactlog_module_server,
     args = list(
@@ -45,3 +47,14 @@ test_that("shiny version is read from Suggests", {
   )
   expect_length(shiny_version_required(), 1)
 })
+
+test_that("module UIs namespace their outputs and can drop the refresh button", {
+  skip_if_not_installed("htmlwidgets")
+  has <- function(ui, text) grepl(text, as.character(ui), fixed = TRUE)
+  for (ui in list(reactlog_module_ui, reactlog_widget_module_ui)) {
+    expect_true(has(ui(id = "x"), "id=\"x-refresh\""))
+    expect_false(has(ui(include_refresh = FALSE, id = "x"), "x-refresh"))
+  }
+  expect_true(has(reactlog_module_ui(id = "x"), "id=\"x-iframe\""))
+  expect_true(has(reactlog_widget_module_ui(id = "x"), "id=\"x-widget\""))
+})
diff --git a/tests/testthat/test-write.R b/tests/testthat/test-write.R
new file mode 100644
index 0000000..e75d839
--- /dev/null
+++ b/tests/testthat/test-write.R
@@ -0,0 +1,25 @@
+log_two_sessions <- function() {
+  structure(list(
+    list(action = "define", reactId = "r1", label = "global", session = NULL),
+    list(action = "define", reactId = "r2", label = "a", session = "a"),
+    list(action = "define", reactId = "r3", label = "b", session = "b")
+  ), version = "1")
+}
+
+test_that("reactlog_write() returns json when `file` is NULL", {
+  json <- reactlog_write(log_two_sessions(), file = NULL)
+  labels <- vapply(jsonlite::fromJSON(json, simplifyVector = FALSE), `[[`, "", "label")
+  expect_equal(labels, c("global", "a", "b"))
+})
+
+test_that("reactlog_write() keeps global and matching session entries", {
+  json <- reactlog_write(log_two_sessions(), file = NULL, session_token = "a")
+  labels <- vapply(jsonlite::fromJSON(json, simplifyVector = FALSE), `[[`, "", "label")
+  expect_equal(labels, c("global", "a"))
+})
+
+test_that("reactlog_write() writes to a file", {
+  file <- withr::local_tempfile(fileext = ".json")
+  reactlog_write(log_two_sessions(), file = file)
+  expect_length(jsonlite::fromJSON(file, simplifyVector = FALSE), 3)
+})