Command tests (#922)

* WIP command tests

* Finish marking todo tests

* update

* update

* Windows cd test ignoring

crates/nu-command/tests/format_conversions/tsv.rs

@@ -0,0 +1,132 @@
+use nu_test_support::fs::Stub::FileWithContentToBeTrimmed;
+use nu_test_support::playground::Playground;
+use nu_test_support::{nu, pipeline};
+
+#[test]
+fn table_to_tsv_text_and_from_tsv_text_back_into_table() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats",
+        "open caco3_plastics.tsv | to tsv | from tsv | first 1 | get origin"
+    );
+
+    assert_eq!(actual.out, "SPAIN");
+}
+
+#[test]
+fn table_to_tsv_text_and_from_tsv_text_back_into_table_using_csv_separator() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats",
+        r"open caco3_plastics.tsv | to tsv | from csv --separator '\t' | first 1 | get origin"
+    );
+
+    assert_eq!(actual.out, "SPAIN");
+}
+
+#[test]
+fn table_to_tsv_text() {
+    Playground::setup("filter_to_tsv_test_1", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContentToBeTrimmed(
+            "tsv_text_sample.txt",
+            r#"
+                importer	shipper	tariff_item	name	origin
+                Plasticos Rival	Reverte	2509000000	Calcium carbonate	Spain
+                Tigre Ecuador	OMYA Andina	3824909999	Calcium carbonate	Colombia
+            "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                open tsv_text_sample.txt
+                | lines
+                | split column "\t" a b c d origin
+                | last 1
+                | to tsv
+                | lines
+                | nth 1
+            "#
+        ));
+
+        assert!(actual.out.contains("Colombia"));
+    })
+}
+
+#[test]
+fn table_to_tsv_text_skipping_headers_after_conversion() {
+    Playground::setup("filter_to_tsv_test_2", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContentToBeTrimmed(
+            "tsv_text_sample.txt",
+            r#"
+                importer    shipper tariff_item name    origin
+                Plasticos Rival Reverte 2509000000  Calcium carbonate   Spain
+                Tigre Ecuador   OMYA Andina 3824909999  Calcium carbonate   Colombia
+            "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                open tsv_text_sample.txt
+                | lines
+                | split column "\t" a b c d origin
+                | last 1
+                | to tsv --noheaders
+            "#
+        ));
+
+        assert!(actual.out.contains("Colombia"));
+    })
+}
+
+#[test]
+fn from_tsv_text_to_table() {
+    Playground::setup("filter_from_tsv_test_1", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContentToBeTrimmed(
+            "los_tres_amigos.txt",
+            r#"
+                first Name	Last Name	rusty_luck
+                Andrés	Robalino	1
+                Jonathan	Turner	1
+                Yehuda	Katz	1
+            "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                open los_tres_amigos.txt
+                | from tsv
+                | get rusty_luck
+                | length
+            "#
+        ));
+
+        assert_eq!(actual.out, "3");
+    })
+}
+
+#[test]
+fn from_tsv_text_skipping_headers_to_table() {
+    Playground::setup("filter_from_tsv_test_2", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContentToBeTrimmed(
+            "los_tres_amigos.txt",
+            r#"
+                Andrés	Robalino	1
+                Jonathan	Turner	1
+                Yehuda	Katz	1
+            "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(), pipeline(
+            r#"
+                open los_tres_amigos.txt
+                | from tsv --noheaders
+                | get Column3
+                | length
+            "#
+        ));
+
+        assert_eq!(actual.out, "3");
+    })
+}