tests: add test_100 for 100.dathere.com & tests for lesson/exercise 0

tests/test_100.rs

@@ -0,0 +1,9 @@
+// The tests in this file and the test_100 folder are for
+// lessons and exercises in the online book "100 exercises with qsv".
+
+// You may read lessons and try out the exercises at:
+// https://100.dathere.com
+
+// Warning: These tests may contain solutions to the exercises.
+
+mod exercise_0;

tests/test_100/exercise_0.rs

@@ -0,0 +1,62 @@
+// Lesson 0: Exploring qsv help messages and syntax
+// https://100.dathere.com/lessons/0/notes.html
+
+use std::process;
+
+use crate::workdir::Workdir;
+
+fn setup(name: &str, command_str: &str, args: Vec<&str>) -> (Workdir, process::Command) {
+    let wrk = Workdir::new(name);
+    wrk.create(
+        "fruits.csv",
+        vec![
+            svec!["fruit", "price"],
+            svec!["apple", "2.50"],
+            svec!["banana", "3.00"],
+            svec!["carrot", "1.50"],
+        ],
+    );
+
+    let mut cmd = wrk.command(command_str);
+    cmd.args(args);
+
+    (wrk, cmd)
+}
+
+// https://100.dathere.com/lessons/0/notes.html#displaying-headers-of-a-csv
+#[test]
+fn fruits_headers() {
+    let name = "fruits_headers";
+    let command_str = "headers";
+    let args = vec!["fruits.csv"];
+    let (wrk, mut cmd) = setup(name, command_str, args);
+
+    let got: String = wrk.stdout(&mut cmd);
+    let expected = r#"1   fruit
+2   price"#;
+    assert_eq!(got, expected);
+}
+
+// https://100.dathere.com/lessons/0/notes.html#exercise-0-total-rows
+#[test]
+fn fruits_count_total() {
+    let name = "fruits_count";
+    let command_str = "count";
+    let args = vec!["fruits.csv", "--no-headers"];
+    let (wrk, mut cmd) = setup(name, command_str, args);
+
+    let got: String = wrk.stdout(&mut cmd);
+    let expected = "4";
+    assert_eq!(got, expected);
+}
+#[test]
+fn fruits_count() {
+    let name = "fruits_count";
+    let command_str = "count";
+    let args = vec!["fruits.csv"];
+    let (wrk, mut cmd) = setup(name, command_str, args);
+
+    let got: String = wrk.stdout(&mut cmd);
+    let expected = "3";
+    assert_eq!(got, expected);
+}

tests/tests.rs

@@ -30,6 +30,7 @@ macro_rules! rassert_eq {
 
 mod workdir;
 
+mod test_100;
 #[cfg(feature = "apply")]
 mod test_apply;
 #[cfg(feature = "datapusher_plus")]