Correctly detect ZI when there is no ziformula (#830)

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: insight
 Title: Easy Access to Model Information for Various Model Objects
-Version: 0.19.6.5
+Version: 0.19.6.6
 Authors@R: 
     c(person(given = "Daniel",
              family = "Lüdecke",

NEWS.md

@@ -20,6 +20,9 @@
 * Fixed issue in `find_formula()` for models of class `gamlss` when the `random()`
   function was used with namespace in the formula (i.e. `... + gamlss::random()`).
 
+* `model_info()` now detects models with zero-inflation part from package
+  *glmmTMB* when models have truncated-families but no `ziformula`.
+
 # insight 0.19.6
 
 ## General

R/model_info.R

@@ -1109,7 +1109,7 @@ model_info.glmmTMB <- function(x, ...) {
   check_if_installed("lme4")
 
   faminfo <- stats::family(x)
-  zero_inflated <- !is_empty_object(lme4::fixef(x)$zi)
+  zero_inflated <- !is_empty_object(lme4::fixef(x)$zi) || startsWith(faminfo$family, "truncated")
 
   .make_family(
     x = x,

tests/testthat/test-glmmTMB.R

@@ -8,7 +8,7 @@ skip_if_not_installed("glmmTMB")
 # fish$livebait <- as.factor(fish$livebait)
 # fish$camper <- as.factor(fish$camper)
 
-data("fish")
+data("fish", package = "insight")
 m1 <- glmmTMB::glmmTMB(
   count ~ child + camper + (1 | persons),
   ziformula = ~ child + camper + (1 | persons),
@@ -970,3 +970,18 @@ test_that("model_info, ordered beta", {
   expect_true(out$is_orderedbeta)
   expect_identical(out$family, "ordbeta")
 })
+
+
+test_that("model_info, recognize ZI even without ziformula", {
+  skip_if_not_installed("glmmTMB")
+  data("fish", package = "insight")
+  fish$count <- fish$count + 1
+  m1 <- glmmTMB::glmmTMB(
+    count ~ child + camper + (1 | persons),
+    data = fish,
+    family = glmmTMB::truncated_nbinom1()
+  )
+  out <- model_info(m1)
+  expect_true(out$is_zero_inflated)
+  expect_true(out$is_hurdle)
+})