1 files changed, 128 insertions, 0 deletions
diff --git a/src/arrow/r/tests/testthat/test-expression.R b/src/arrow/r/tests/testthat/test-expression.R
new file mode 100644
index 000000000..c4aab718d
--- /dev/null
+++ b/src/arrow/r/tests/testthat/test-expression.R
@@ -0,0 +1,128 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+
+test_that("C++ expressions", {
+  skip_if_not_available("dataset")
+  f <- Expression$field_ref("f")
+  expect_identical(f$field_name, "f")
+  g <- Expression$field_ref("g")
+  date <- Expression$scalar(as.Date("2020-01-15"))
+  ts <- Expression$scalar(as.POSIXct("2020-01-17 11:11:11"))
+  i64 <- Expression$scalar(bit64::as.integer64(42))
+  time <- Expression$scalar(hms::hms(56, 34, 12))
+
+  expect_r6_class(f == g, "Expression")
+  expect_r6_class(f == 4, "Expression")
+  expect_r6_class(f == "", "Expression")
+  expect_r6_class(f == NULL, "Expression")
+  expect_r6_class(f == date, "Expression")
+  expect_r6_class(f == i64, "Expression")
+  expect_r6_class(f == time, "Expression")
+  # can't seem to make this work right now because of R Ops.method dispatch
+  # expect_r6_class(f == as.Date("2020-01-15"), "Expression") # nolint
+  expect_r6_class(f == ts, "Expression")
+  expect_r6_class(f <= 2L, "Expression")
+  expect_r6_class(f != FALSE, "Expression")
+  expect_r6_class(f > 4, "Expression")
+  expect_r6_class(f < 4 & f > 2, "Expression")
+  expect_r6_class(f < 4 | f > 2, "Expression")
+  expect_r6_class(!(f < 4), "Expression")
+  expect_output(
+    print(f > 4),
+    "Expression\n(f > 4)",
+    fixed = TRUE
+  )
+  expect_equal(
+    f$type(schema(f = float64())),
+    float64()
+  )
+  expect_equal(
+    (f > 4)$type(schema(f = float64())),
+    bool()
+  )
+  # Interprets that as a list type
+  expect_r6_class(f == c(1L, 2L), "Expression")
+
+  expect_error(
+    Expression$create("add", 1, 2),
+    "Expression arguments must be Expression objects"
+  )
+})
+
+test_that("Field reference expression schemas and types", {
+  x <- Expression$field_ref("x")
+
+  # type() throws error when schema is NULL
+  expect_error(x$type(), "schema")
+
+  # type() returns type when schema is set
+  x$schema <- Schema$create(x = int32())
+  expect_equal(x$type(), int32())
+})
+
+test_that("Scalar expression schemas and types", {
+  # type() works on scalars without setting the schema
+  expect_equal(
+    Expression$scalar("foo")$type(),
+    arrow::string()
+  )
+  expect_equal(
+    Expression$scalar(42L)$type(),
+    int32()
+  )
+})
+
+test_that("Expression schemas and types", {
+  x <- Expression$field_ref("x")
+  y <- Expression$field_ref("y")
+  z <- Expression$scalar(42L)
+
+  # type() throws error when both schemas are unset
+  expect_error(
+    Expression$create("add_checked", x, y)$type(),
+    "schema"
+  )
+
+  # type() throws error when left schema is unset
+  y$schema <- Schema$create(y = float64())
+  expect_error(
+    Expression$create("add_checked", x, y)$type(),
+    "schema"
+  )
+
+  # type() throws error when right schema is unset
+  x$schema <- Schema$create(x = int32())
+  y$schema <- NULL
+  expect_error(
+    Expression$create("add_checked", x, y)$type(),
+    "schema"
+  )
+
+  # type() returns type when both schemas are set
+  y$schema <- Schema$create(y = float64())
+  expect_equal(
+    Expression$create("add_checked", x, y)$type(),
+    float64()
+  )
+
+  # type() returns type when one arg has schema set and one is scalar
+  expect_equal(
+    Expression$create("add_checked", x, z)$type(),
+    int32()
+  )
+})