feat: smart_tab

Implement `smart_tab`, which optionally makes the tab key run the
`move_parent_node_start` command when the cursor has non- whitespace to
its left.

1 files changed, 253 insertions, 0 deletions

diff --git a/helix-term/tests/test/commands/movement.rs b/helix-term/tests/test/commands/movement.rs
index 03dc7ba9..5be68837 100644
--- a/helix-term/tests/test/commands/movement.rs
+++ b/helix-term/tests/test/commands/movement.rs
@@ -197,3 +197,256 @@ async fn test_move_parent_node_start() -> anyhow::Result<()> {
 
     Ok(())
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn test_smart_tab_move_parent_node_end() -> anyhow::Result<()> {
+    let tests = vec![
+        // single cursor stays single cursor, first goes to end of current
+        // node, then parent
+        (
+            helpers::platform_line(indoc! {r##"
+                fn foo() {
+                    let result = if true {
+                        "yes"
+                    } else {
+                        "no#["|]#
+                    }
+                }
+            "##}),
+            "i<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no\"#[|\n]#
+                    }
+                }
+            "}),
+        ),
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no\"#[\n|]#
+                    }
+                }
+            "}),
+            "i<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no\"
+                    }#[|\n]#
+                }
+            "}),
+        ),
+        // appending to the end of a line should still look at the current
+        // line, not the next one
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no#[\"|]#
+                    }
+                }
+            "}),
+            "a<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no\"
+                    }#[\n|]#
+                }
+            "}),
+        ),
+        // before cursor is all whitespace, so insert tab
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        #[\"no\"|]#
+                    }
+                }
+            "}),
+            "i<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                            #[|\"no\"]#
+                    }
+                }
+            "}),
+        ),
+        // if selection spans multiple lines, it should still only look at the
+        // line on which the head is
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        #[\"yes\"
+                    } else {
+                        \"no\"|]#
+                    }
+                }
+            "}),
+            "a<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    } else {
+                        \"no\"
+                    }#[\n|]#
+                }
+            "}),
+        ),
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        #[\"yes\"
+                    } else {
+                        \"no\"|]#
+                    }
+                }
+            "}),
+            "i<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                            #[|\"yes\"
+                    } else {
+                        \"no\"]#
+                    }
+                }
+            "}),
+        ),
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    #[l|]#et result = if true {
+                        #(\"yes\"
+                    } else {
+                        \"no\"|)#
+                    }
+                }
+            "}),
+            "i<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                        #[|l]#et result = if true {
+                            #(|\"yes\"
+                    } else {
+                        \"no\")#
+                    }
+                }
+            "}),
+        ),
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"#[\n|]#
+                    } else {
+                        \"no\"#(\n|)#
+                    }
+                }
+            "}),
+            "i<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    }#[| ]#else {
+                        \"no\"
+                    }#(|\n)#
+                }
+            "}),
+        ),
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        #[\"yes\"|]#
+                    } else {
+                        #(\"no\"|)#
+                    }
+                }
+            "}),
+            "i<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                            #[|\"yes\"]#
+                    } else {
+                            #(|\"no\")#
+                    }
+                }
+            "}),
+        ),
+        // if any cursors are not preceded by all whitespace, then do the
+        // smart_tab action
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        #[\"yes\"\n|]#
+                    } else {
+                        \"no#(\"\n|)#
+                    }
+                }
+            "}),
+            "i<tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        \"yes\"
+                    }#[| ]#else {
+                        \"no\"
+                    }#(|\n)#
+                }
+            "}),
+        ),
+        // Ctrl-tab always inserts a tab
+        (
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                        #[\"yes\"\n|]#
+                    } else {
+                        \"no#(\"\n|)#
+                    }
+                }
+            "}),
+            "i<S-tab>",
+            helpers::platform_line(indoc! {"\
+                fn foo() {
+                    let result = if true {
+                            #[|\"yes\"\n]#
+                    } else {
+                        \"no    #(|\"\n)#
+                    }
+                }
+            "}),
+        ),
+    ];
+
+    for test in tests {
+        test_with_config(AppBuilder::new().with_file("foo.rs", None), test).await?;
+    }
+
+    Ok(())
+}