Merge pull request #66 from tidymodels/glmnet-linear_reg

glmnet tests for `linear_reg()`

Author: hfrick

tests/testthat/_snaps/glmnet-linear.md

@@ -0,0 +1,18 @@
+# error traps
+
+    Code
+      linear_reg(penalty = 0.01) %>% set_engine("glmnet") %>% fit(mpg ~ ., data = mtcars[
+        -(1:4), ]) %>% predict(mtcars[-(1:4), ], penalty = 0:1)
+    Error <rlang_error>
+      `penalty` should be a single numeric value. `multi_predict()` can be used to get multiple predictions per row of data.
+
+---
+
+    Code
+      linear_reg() %>% set_engine("glmnet") %>% fit(mpg ~ ., data = mtcars[-(1:4), ])
+    Error <rlang_error>
+      For the glmnet engine, `penalty` must be a single number (or a value of `tune()`).
+      * There are 0 values for `penalty`.
+      * To try multiple values for total regularization, use the tune package.
+      * To predict multiple penalties, use `multi_predict()`
+