Path Enhancement Project #2: parse, join and split (#3256)

* Add new path parse subcommand

This includes a slight refactor to all the path subcommand `action()`
functions.

* Remove filestem and extension; Fix example

* Add additional description to path parse

* Put join arg behind flag; Fix missing import (Win)

* Fix error when column path is passed as arg

* Add structured path joining

Structured path is implicitly joined at every patch subcommand call.

* Fix existing path join tests; Fix rustfmt

* Remove redundant 'static lifetime (clippy)

* Add initial impl of path split subcommand

* Add ability to join path from parts

* Fix wrong results in path split examples

* Fix remaining asyncs after engine change

* Do not wrap split path parts into table

When the input is just a list of values, the `path split` command will
split each value directly into the output stream, similar to
`split-row`. Column path--specified values are still wrapped into a
table so they can still be used to replace table fields.

* Join list of values instead of going one-by-one

When `path join` encounters a list of values, it attempts to join them,
instead of going one-by-one like the rest of the path commands. You can
still `each { echo $it | path join }` to join them one-by-one, if the
values are, e.g., tables.

Now, the behavior of `path split` and `path join` should match the
`split-row` and `str collect` counterparts and should hopefully align
better with user's expectations.

* Make sure path join detects structured path

* Fix panic on empty input stream

Also, doesn't collect input into vector unnecessarily.

* Fix path join not appending value

* Remove argument serialization

* Make better errors; Misc refactor

* OsStr -> String encoding is now lossy, instead of throwing an error
* The consequence is action() now always returns Value instead of Result
* Removed redundant handle_value() call in `path join`
* Fix possible incorrect error detection in `path split`
* Applied rustfmt + clippy

* Add more usage, examples & test; Fix type error

The 'parent' column was required to be a path but didn't work with
string.

* Add more help & examples; Maybe fix Windows error

* Refactor operate function

Reducing code repetition

* Review usages and examples

* Add the option to manually specify the extension

* Add more tests; Fix failures on Windows

* Move path commands to engine-p

* Small refactor

crates/nu-command/tests/commands/path/extension.rs

@@ -1,37 +0,0 @@
-use nu_test_support::{nu, pipeline};
-
-#[test]
-fn returns_extension_of_path_ending_with_dot() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "bacon." | path extension
-        "#
-    ));
-
-    assert_eq!(actual.out, "");
-}
-
-#[test]
-fn replaces_extension_with_dot_of_path_ending_with_dot() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "bacon." | path extension -r .egg
-        "#
-    ));
-
-    assert_eq!(actual.out, "bacon..egg");
-}
-
-#[test]
-fn replaces_extension_of_empty_path() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "" | path extension -r egg
-        "#
-    ));
-
-    assert_eq!(actual.out, "");
-}

crates/nu-command/tests/commands/path/filestem.rs

@@ -1,95 +0,0 @@
-use nu_test_support::{nu, pipeline};
-
-use super::join_path_sep;
-
-#[test]
-fn returns_filestem_of_dot() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "menu/eggs/." 
-            | path filestem
-        "#
-    ));
-
-    assert_eq!(actual.out, "eggs");
-}
-
-#[test]
-fn returns_filestem_of_double_dot() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "menu/eggs/.." 
-            | path filestem
-        "#
-    ));
-
-    assert_eq!(actual.out, "");
-}
-
-#[test]
-fn returns_filestem_of_path_with_empty_prefix() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "menu/spam.txt" 
-            | path filestem -p ""
-        "#
-    ));
-
-    assert_eq!(actual.out, "spam");
-}
-
-#[test]
-fn returns_filestem_of_path_with_empty_suffix() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "menu/spam.txt" 
-            | path filestem -s ""
-        "#
-    ));
-
-    assert_eq!(actual.out, "spam.txt");
-}
-
-#[test]
-fn returns_filestem_of_path_with_empty_prefix_and_suffix() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "menu/spam.txt" 
-            | path filestem -p "" -s ""
-        "#
-    ));
-
-    assert_eq!(actual.out, "spam.txt");
-}
-
-#[test]
-fn returns_filestem_with_wrong_prefix_and_suffix() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "menu/spam.txt" 
-            | path filestem -p "bacon" -s "eggs"
-        "#
-    ));
-
-    assert_eq!(actual.out, "spam.txt");
-}
-
-#[test]
-fn replaces_filestem_stripped_to_dot() {
-    let actual = nu!(
-        cwd: "tests", pipeline(
-        r#"
-            echo "menu/spam.txt" 
-            | path filestem -p "spam" -s "txt" -r ".eggs."
-        "#
-    ));
-
-    let expected = join_path_sep(&["menu", "spam.eggs.txt"]);
-    assert_eq!(actual.out, expected);
-}

crates/nu-command/tests/commands/path/join.rs

@@ -8,7 +8,7 @@ fn returns_path_joined_with_column_path() {
         cwd: "tests", pipeline(
         r#"
             echo [ [name]; [eggs] ]
-            | path join spam.txt name
+            | path join -a spam.txt name
             | get name
         "#
     ));
@@ -17,13 +17,27 @@ fn returns_path_joined_with_column_path() {
     assert_eq!(actual.out, expected);
 }
 
+#[test]
+fn returns_path_joined_from_list() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo [ home viking spam.txt ]
+            | path join 
+        "#
+    ));
+
+    let expected = join_path_sep(&["home", "viking", "spam.txt"]);
+    assert_eq!(actual.out, expected);
+}
+
 #[test]
 fn appends_slash_when_joined_with_empty_path() {
     let actual = nu!(
         cwd: "tests", pipeline(
         r#"
             echo "/some/dir"
-            | path join ''
+            | path join -a ''
         "#
     ));
 
@@ -37,7 +51,7 @@ fn returns_joined_path_when_joining_empty_path() {
         cwd: "tests", pipeline(
         r#"
             echo ""
-            | path join foo.txt
+            | path join -a foo.txt
         "#
     ));
 

crates/nu-command/tests/commands/path/mod.rs

@@ -2,9 +2,9 @@ mod basename;
 mod dirname;
 mod exists;
 mod expand;
-mod extension;
-mod filestem;
 mod join;
+mod parse;
+mod split;
 mod type_;
 
 use std::path::MAIN_SEPARATOR;

crates/nu-command/tests/commands/path/parse.rs

@@ -0,0 +1,136 @@
+use nu_test_support::{nu, pipeline};
+
+#[cfg(windows)]
+#[test]
+fn parses_single_path_prefix() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo 'C:\users\viking\spam.txt'
+            | path parse
+            | get prefix
+        "#
+    ));
+
+    assert_eq!(actual.out, "C:");
+}
+
+#[test]
+fn parses_single_path_parent() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo 'home/viking/spam.txt'
+            | path parse
+            | get parent
+        "#
+    ));
+
+    assert_eq!(actual.out, "home/viking");
+}
+
+#[test]
+fn parses_single_path_stem() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo 'home/viking/spam.txt'
+            | path parse
+            | get stem
+        "#
+    ));
+
+    assert_eq!(actual.out, "spam");
+}
+
+#[test]
+fn parses_custom_extension_gets_extension() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo 'home/viking/spam.tar.gz' 
+            | path parse -e tar.gz
+            | get extension
+        "#
+    ));
+
+    assert_eq!(actual.out, "tar.gz");
+}
+
+#[test]
+fn parses_custom_extension_gets_stem() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo 'home/viking/spam.tar.gz' 
+            | path parse -e tar.gz
+            | get stem
+        "#
+    ));
+
+    assert_eq!(actual.out, "spam");
+}
+
+#[test]
+fn parses_ignoring_extension_gets_extension() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo 'home/viking/spam.tar.gz' 
+            | path parse -e ''
+            | get extension
+        "#
+    ));
+
+    assert_eq!(actual.out, "");
+}
+
+#[test]
+fn parses_ignoring_extension_gets_stem() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo 'home/viking/spam.tar.gz' 
+            | path parse -e ""
+            | get stem
+        "#
+    ));
+
+    assert_eq!(actual.out, "spam.tar.gz");
+}
+
+#[test]
+fn parses_column_path_extension() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo [[home, barn]; ['home/viking/spam.txt', 'barn/cow/moo.png']]
+            | path parse home barn
+            | get barn
+            | get extension
+        "#
+    ));
+
+    assert_eq!(actual.out, "png");
+}
+
+#[test]
+fn parses_into_correct_number_of_columns() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo 'home/viking/spam.txt'
+            | path parse
+            | pivot
+            | get Column0
+            | length
+        "#
+    ));
+
+    #[cfg(windows)]
+    let expected = "4";
+    #[cfg(not(windows))]
+    let expected = "3";
+
+    assert_eq!(actual.out, expected);
+}

crates/nu-command/tests/commands/path/split.rs

@@ -0,0 +1,47 @@
+use nu_test_support::{nu, pipeline};
+
+#[test]
+fn splits_empty_path() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo '' | path split
+        "#
+    ));
+
+    assert_eq!(actual.out, "");
+}
+
+#[test]
+fn splits_correctly_single_path() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo ['home/viking/spam.txt']
+            | path split 
+            | last
+        "#
+    ));
+
+    assert_eq!(actual.out, "spam.txt");
+}
+
+#[test]
+fn splits_correctly_with_column_path() {
+    let actual = nu!(
+        cwd: "tests", pipeline(
+        r#"
+            echo [
+                [home, barn];
+
+                ['home/viking/spam.txt', 'barn/cow/moo.png']
+                ['home/viking/eggs.txt', 'barn/goat/cheese.png']
+            ]
+            | path split home barn
+            | get barn
+            | length
+        "#
+    ));
+
+    assert_eq!(actual.out, "6");
+}