Add additional test cases

These test cases try to cover various edge cases. For example, comments
around the else keyword and long, unbreakable, single-line initializer
expressions, and long patterns.

Author: ytmimi

tests/source/let_else.rs

@@ -1,14 +1,147 @@
 fn main() {
+    // Although this won't compile it still parses so make sure we can format empty else blocks
+    let Some(x) = opt else {};
+
+    // let-else may be formatted on a single line if they are "short"
+    // and only contain a single expression
     let Some(x) = opt else { return };
 
+    let Some(x) = opt else {
+        return
+    };
+
     let Some(x) = opt else { return; };
 
     let Some(x) = opt else {
         // nope
         return;
     };
 
+    let Some(x) = opt else { let y = 1; return y };
+
     let Some(x) = y.foo("abc", fairly_long_identifier, "def", "123456", "string", "cheese") else { bar() };
 
     let Some(x) = abcdef().foo("abc", some_really_really_really_long_ident, "ident", "123456").bar().baz().qux("fffffffffffffffff") else { foo_bar() };
 }
+
+fn with_comments_around_else_keyword() {
+    let Some(x) = opt /* pre else keyword block-comment */ else { return };
+
+    let Some(x) = opt else /* post else keyword block-comment */ { return };
+
+    let Some(x) = opt /* pre else keyword block-comment */ else /* post else keyword block-comment */ { return };
+
+    let Some(x) = opt // pre else keyword line-comment
+    else { return };
+
+    let Some(x) = opt else
+     // post else keyword line-comment
+    { return };
+
+    let Some(x) = opt // pre else keyword line-comment
+    else
+    // post else keyword line-comment
+    { return };
+
+}
+
+fn unbreakable_initializer_expr_pre_formatting_let_else_length_near_max_width() {
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else block;` is 100 (max_width)
+    // Post Formatting:
+    // The formatting is left unchanged!
+    let Some(x) = some_really_really_really_really_really_really_really_long_name_A else { return };
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else block;` is 100 (max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // and the else block is formatted over multiple lines because we can't fit the
+    // else block on the same line as the initializer expr.
+    let Some(x) = some_really_really_really_really_really_really_really_long_name___B else {return};
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else block;` is 100 (max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // and the else block is formatted over multiple lines because we can't fit the
+    // else block on the same line as the initializer expr.
+    let Some(x) = some_really_really_really_really_long_name_____C else {some_divergent_function()};
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else block;` is 101 (> max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // and the else block is formatted over multiple lines because we can't fit the
+    // else block on the same line as the initializer expr.
+    let Some(x) = some_really_really_really_really_really_really_really_long_name__D else { return };
+}
+
+fn unbreakable_initializer_expr_pre_formatting_length_up_to_opening_brace_near_max_width() {
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else {` is 100 (max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // and the else block is formatted over multiple lines because we can't fit the
+    // else block on the same line as the initializer expr.
+    let Some(x) = some_really_really_really_really_really_really_really_really_long_name____E else {return};
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else {` is 101 (> max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // which leads to the `{` exceeding the max width
+    let Some(x) = some_really_really_really_really_really_really_really_really_long_name_____F else {return};
+}
+
+fn unbreakable_initializer_expr_pre_formatting_length_through_initializer_expr_near_max_width() {
+    // Pre Formatting:
+    // The length of `(indent)let pat = init` is 99 (< max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // which leads to the `else {` exceeding the max width
+    let Some(x) = some_really_really_really_really_really_really_really_really_really_long_name___G else {return};
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init` is 100 (max_width)
+    // Post Formatting:
+    // Break after the `=` and put the initializer expr on it's own line.
+    // Because the initializer expr is multi-lined the else is placed on it's own line.
+    let Some(x) = some_really_really_really_really_really_really_really_really_really_long_name____H else {return};
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init` is 109 (> max_width)
+    // Post Formatting:
+    // Break after the `=` and put the initializer expr on it's own line.
+    // Because the initializer expr is multi-lined the else is placed on it's own line.
+    // The initializer expr has a length of 91, which when indented on the next line
+    // The `(indent)init` line has a lengh of 99. This is the max length that the `init` can be
+    // before we start running into max_width issues. I suspect this is becuase the shape is
+    // accounting for the `;` at the end of the `let-else` statement.
+    let Some(x) = some_really_really_really_really_really_really_really_really_really_really_long_name______I else {return};
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init` is 110 (> max_width)
+    // Post Formatting:
+    // Max length issues prevent us from formatting.
+    // The initializer expr has a length of 92, which if it would be indented on the next line
+    // the `(indent)init` line has a lengh of 100 which == max_width of 100.
+    // One might expect formatting to succeed, but I suspect the reason we hit max_width issues is
+    // because the Shape is accounting for the `;` at the end of the `let-else` statement.
+    let Some(x) = some_really_really_really_really_really_really_really_really_really_really_really_long_nameJ else {return};
+}
+
+fn long_patterns() {
+    let Foo {x: Bar(..), y: FooBar(..), z: Baz(..)} = opt else {
+        return;
+    };
+
+    // with version=One we don't wrap long array patterns
+    let [aaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbb, cccccccccccccccccc, dddddddddddddddddd] = opt else {
+        return;
+    };
+
+    let Some(Ok((Message::ChangeColor(super::color::Color::Rgb(r, g, b)), Point { x, y, z }))) = opt else {
+        return;
+    };
+}

tests/target/let_else.rs

@@ -1,4 +1,11 @@
 fn main() {
+    // Although this won't compile it still parses so make sure we can format empty else blocks
+    let Some(x) = opt else {};
+
+    // let-else may be formatted on a single line if they are "short"
+    // and only contain a single expression
+    let Some(x) = opt else { return };
+
     let Some(x) = opt else { return };
 
     let Some(x) = opt else {
@@ -10,6 +17,11 @@ fn main() {
         return;
     };
 
+    let Some(x) = opt else {
+        let y = 1;
+        return y;
+    };
+
     let Some(x) = y.foo(
         "abc",
         fairly_long_identifier,
@@ -35,3 +47,173 @@ fn main() {
         foo_bar()
     };
 }
+
+fn with_comments_around_else_keyword() {
+    let Some(x) = opt
+    /* pre else keyword block-comment */
+    else {
+        return;
+    };
+
+    let Some(x) = opt else
+    /* post else keyword block-comment */
+    {
+        return;
+    };
+
+    let Some(x) = opt
+    /* pre else keyword block-comment */
+    else
+    /* post else keyword block-comment */
+    {
+        return;
+    };
+
+    let Some(x) = opt
+    // pre else keyword line-comment
+    else {
+        return;
+    };
+
+    let Some(x) = opt else
+    // post else keyword line-comment
+    {
+        return;
+    };
+
+    let Some(x) = opt
+    // pre else keyword line-comment
+    else
+    // post else keyword line-comment
+    {
+        return;
+    };
+}
+
+fn unbreakable_initializer_expr_pre_formatting_let_else_length_near_max_width() {
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else block;` is 100 (max_width)
+    // Post Formatting:
+    // The formatting is left unchanged!
+    let Some(x) = some_really_really_really_really_really_really_really_long_name_A else { return };
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else block;` is 100 (max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // and the else block is formatted over multiple lines because we can't fit the
+    // else block on the same line as the initializer expr.
+    let Some(x) = some_really_really_really_really_really_really_really_long_name___B else {
+        return;
+    };
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else block;` is 100 (max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // and the else block is formatted over multiple lines because we can't fit the
+    // else block on the same line as the initializer expr.
+    let Some(x) = some_really_really_really_really_long_name_____C else {
+        some_divergent_function()
+    };
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else block;` is 101 (> max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // and the else block is formatted over multiple lines because we can't fit the
+    // else block on the same line as the initializer expr.
+    let Some(x) = some_really_really_really_really_really_really_really_long_name__D else {
+        return;
+    };
+}
+
+fn unbreakable_initializer_expr_pre_formatting_length_up_to_opening_brace_near_max_width() {
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else {` is 100 (max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // and the else block is formatted over multiple lines because we can't fit the
+    // else block on the same line as the initializer expr.
+    let Some(x) = some_really_really_really_really_really_really_really_really_long_name____E else {
+        return;
+    };
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init else {` is 101 (> max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // which leads to the `{` exceeding the max width
+    let Some(x) = some_really_really_really_really_really_really_really_really_long_name_____F else {
+        return;
+    };
+}
+
+fn unbreakable_initializer_expr_pre_formatting_length_through_initializer_expr_near_max_width() {
+    // Pre Formatting:
+    // The length of `(indent)let pat = init` is 99 (< max_width)
+    // Post Formatting:
+    // The else keyword and opening brace remain on the same line as the initializer expr,
+    // which leads to the `else {` exceeding the max width
+    let Some(x) = some_really_really_really_really_really_really_really_really_really_long_name___G else {
+        return;
+    };
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init` is 100 (max_width)
+    // Post Formatting:
+    // Break after the `=` and put the initializer expr on it's own line.
+    // Because the initializer expr is multi-lined the else is placed on it's own line.
+    let Some(x) =
+        some_really_really_really_really_really_really_really_really_really_long_name____H
+    else {
+        return;
+    };
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init` is 109 (> max_width)
+    // Post Formatting:
+    // Break after the `=` and put the initializer expr on it's own line.
+    // Because the initializer expr is multi-lined the else is placed on it's own line.
+    // The initializer expr has a length of 91, which when indented on the next line
+    // The `(indent)init` line has a lengh of 99. This is the max length that the `init` can be
+    // before we start running into max_width issues. I suspect this is becuase the shape is
+    // accounting for the `;` at the end of the `let-else` statement.
+    let Some(x) =
+        some_really_really_really_really_really_really_really_really_really_really_long_name______I
+    else {
+        return;
+    };
+
+    // Pre Formatting:
+    // The length of `(indent)let pat = init` is 110 (> max_width)
+    // Post Formatting:
+    // Max length issues prevent us from formatting.
+    // The initializer expr has a length of 92, which if it would be indented on the next line
+    // the `(indent)init` line has a lengh of 100 which == max_width of 100.
+    // One might expect formatting to succeed, but I suspect the reason we hit max_width issues is
+    // because the Shape is accounting for the `;` at the end of the `let-else` statement.
+    let Some(x) = some_really_really_really_really_really_really_really_really_really_really_really_long_nameJ else {return};
+}
+
+fn long_patterns() {
+    let Foo {
+        x: Bar(..),
+        y: FooBar(..),
+        z: Baz(..),
+    } = opt
+    else {
+        return;
+    };
+
+    // with version=One we don't wrap long array patterns
+    let [aaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbb, cccccccccccccccccc, dddddddddddddddddd] = opt else {
+        return;
+    };
+
+    let Some(Ok((Message::ChangeColor(super::color::Color::Rgb(r, g, b)), Point { x, y, z }))) =
+        opt
+    else {
+        return;
+    };
+}