Retain line ending by default.

.gitattributes

@@ -2,3 +2,15 @@ tests/issue0228.d               text eol=lf
 tests/allman/issue0228.d.ref    text eol=crlf
 tests/knr/issue0228.d.ref       text eol=crlf
 tests/otbs/issue0228.d.ref      text eol=crlf
+tests/issue0552_lf.d            text eol=lf
+tests/allman/issue0552_lf.d.ref text eol=lf
+tests/knr/issue0552_lf.d.ref    text eol=lf
+tests/otbs/issue0552_lf.d.ref   text eol=lf
+tests/issue0552_cr.d            text eol=cr
+tests/allman/issue0552_cr.d.ref text eol=cr
+tests/knr/issue0552_cr.d.ref    text eol=cr
+tests/otbs/issue0552_cr.d.ref   text eol=cr
+tests/issue0552_crlf.d            text eol=crlf
+tests/allman/issue0552_crlf.d.ref text eol=crlf
+tests/knr/issue0552_crlf.d.ref    text eol=crlf
+tests/otbs/issue0552_crlf.d.ref   text eol=crlf

README.md

@@ -91,7 +91,7 @@ void main(string[] args)
 ### Standard EditorConfig properties
 Property Name | Allowed Values | Description
 --------------|----------------|------------
-end_of_line | `cr`, `crlf` and **`lf`** | [See EditorConfig documentation.](https://github.com/editorconfig/editorconfig/wiki/EditorConfig-Properties#end_of_line)
+end_of_line | `cr`, `crlf` and `lf` | [See EditorConfig documentation.](https://github.com/editorconfig/editorconfig/wiki/EditorConfig-Properties#end_of_line) When not set, `dfmt` adopts the first line ending in the input.
 insert_final_newline | **`true`** | Not supported. `dfmt` always inserts a final newline.
 charset | **`UTF-8`** | Not supported. `dfmt` only works correctly on UTF-8.
 indent_style | `tab`, **`space`** | [See EditorConfig documentation.](https://github.com/editorconfig/editorconfig/wiki/EditorConfig-Properties#indent_style)

src/dfmt/config.d

@@ -10,7 +10,7 @@ import dfmt.editorconfig;
 /// Brace styles
 enum BraceStyle
 {
-    unspecified,
+    _unspecified,
     /// $(LINK https://en.wikipedia.org/wiki/Indent_style#Allman_style)
     allman,
     /// $(LINK https://en.wikipedia.org/wiki/Indent_style#Variant:_1TBS)
@@ -23,7 +23,7 @@ enum BraceStyle
 
 enum TemplateConstraintStyle
 {
-    unspecified,
+    _unspecified,
     conditional_newline_indent,
     conditional_newline,
     always_newline,
@@ -73,7 +73,7 @@ struct Config
     void initializeWithDefaults()
     {
         pattern = "*.d";
-        end_of_line = EOL.lf;
+        end_of_line = EOL._default;
         indent_style = IndentStyle.space;
         indent_size = 4;
         tab_width = 4;

src/dfmt/editorconfig.d

@@ -26,21 +26,22 @@ private auto commentRe = ctRegex!(`^\s*[#;].*$`);
 
 enum OptionalBoolean : ubyte
 {
-    unspecified = 3,
+    _unspecified = 3,
     t = 1,
     f = 0
 }
 
 enum IndentStyle : ubyte
 {
-    unspecified,
+    _unspecified,
     tab,
     space
 }
 
 enum EOL : ubyte
 {
-    unspecified,
+    _unspecified,
+    _default,
     lf,
     cr,
     crlf
@@ -74,7 +75,7 @@ mixin template StandardEditorConfigFields()
             static if (N == "pattern")
                 continue;
             else static if (is(T == enum))
-                *thisN = otherN != T.unspecified ? otherN : *thisN;
+                *thisN = otherN != T._unspecified ? otherN : *thisN;
             else static if (is(T == int))
                 *thisN = otherN != -1 ? otherN : *thisN;
             else static if (is(T == string))

src/dfmt/formatter.d

@@ -121,8 +121,13 @@ struct TokenFormatter(OutputRange)
                 this.eolString = "\n";
             else if (eol == eol.crlf)
                 this.eolString = "\r\n";
-            else if (eol == eol.unspecified)
+            else if (eol == eol._unspecified)
                 assert(false, "config.end_of_line was unspecified");
+            else
+            {
+                assert (eol == eol._default);
+                this.eolString = eolStringFromInput;
+            }
         }
     }
 
@@ -201,6 +206,17 @@ private:
     /// and paren indentation is ignored.line breaks and "[" reset the counter.
     int parenDepthOnLine;
 
+    string eolStringFromInput() const
+    {
+        import std.algorithm : countUntil;
+
+        // Intentional wraparound, -1 turns into uint.max when not found:
+        const firstCR = cast(uint) rawSource.countUntil("\r");
+        if (firstCR < cast(uint) rawSource.countUntil("\n"))
+            return firstCR == rawSource.countUntil("\r\n") ? "\r\n" : "\r";
+        return "\n";
+    }
+
     void formatStep()
     {
         import std.range : assumeSorted;
@@ -376,7 +392,7 @@ private:
         import dfmt.editorconfig : OB = OptionalBoolean;
         with (TemplateConstraintStyle) final switch (config.dfmt_template_constraint_style)
         {
-        case unspecified:
+        case _unspecified:
             assert(false, "Config was not validated properly");
         case conditional_newline:
             immutable l = currentLineLength + betweenParenLength(tokens[index + 1 .. $]);

src/dfmt/main.d

@@ -289,12 +289,14 @@ private version (Windows)
 
 template optionsToString(E) if (is(E == enum))
 {
+    import std.algorithm.searching : startsWith;
+
     enum optionsToString = () {
 
         string result = "(";
         foreach (s; [__traits(allMembers, E)])
         {
-            if (s != "unspecified")
+            if (!s.startsWith("_"))
                 result ~= s ~ "|";
         }
         result = result[0 .. $ - 1] ~ ")";

tests/allman/issue0552_cr.d.ref

@@ -0,0 +1 @@
+/// Testing CR line endings.void main(){}

tests/allman/issue0552_crlf.d.ref

@@ -0,0 +1,4 @@
+/// Testing CRLF line endings.
+void main()
+{
+}

tests/allman/issue0552_lf.d.ref

@@ -0,0 +1,4 @@
+/// Testing LF line endings.
+void main()
+{
+}

tests/issue0552_cr.d

@@ -0,0 +1 @@
+/// Testing CR line endings.void main(){}

tests/issue0552_crlf.d

@@ -0,0 +1,4 @@
+/// Testing CRLF line endings.
+void main()
+{
+}

tests/issue0552_lf.d

@@ -0,0 +1,4 @@
+/// Testing LF line endings.
+void main()
+{
+}

tests/knr/issue0552_cr.d.ref

@@ -0,0 +1 @@
+/// Testing CR line endings.void main(){}

tests/knr/issue0552_crlf.d.ref

@@ -0,0 +1,4 @@
+/// Testing CRLF line endings.
+void main()
+{
+}

tests/knr/issue0552_lf.d.ref

@@ -0,0 +1,4 @@
+/// Testing LF line endings.
+void main()
+{
+}

tests/otbs/issue0552_cr.d.ref

@@ -0,0 +1 @@
+/// Testing CR line endings.void main() {}

tests/otbs/issue0552_crlf.d.ref

@@ -0,0 +1,3 @@
+/// Testing CRLF line endings.
+void main() {
+}

tests/otbs/issue0552_lf.d.ref

@@ -0,0 +1,3 @@
+/// Testing LF line endings.
+void main() {
+}

tests/test.d

@@ -29,13 +29,10 @@ int main()
             if (const result = spawnProcess(dfmtCommand, stdin, File(outFileName, "w")).wait)
                 return result;
 
-            // As long as dfmt defaults to LF line endings (issue #552), we'll have to default to ignore
-            // the line endings in our verification with the reference.
-            const keepTerminator = dfmtCommand.any!(a => a.canFind("--end_of_line")).to!(Flag!"keepTerminator");
             const outText = outFileName.readText;
             const refText = refFileName.readText;
-            const outLines = outText.splitLines(keepTerminator);
-            const refLines = refText.splitLines(keepTerminator);
+            const outLines = outText.splitLines(Yes.keepTerminator);
+            const refLines = refText.splitLines(Yes.keepTerminator);
             foreach (i; 0 .. min(refLines.length, outLines.length))
                 if (outLines[i] != refLines[i])
                 {
@@ -56,26 +53,6 @@ int main()
                 writefln("%(%s%)", [outLines[refLines.length]]);
                 return 1;
             }
-
-            // As long as dfmt defaults to LF line endings (issue #552) we need an explicit trailing newline check.
-            // because a) splitLines gives the same number of lines regardless whether the last line ends with a newline,
-            // and b) when line endings are ignored the trailing endline is of course also ignored.
-            if (outText.endsWithNewline)
-            {
-                if (!refText.endsWithNewline)
-                {
-                    writeln(outFileName, " ends with a newline, but ", refFileName, " does not.");
-                    return 1;
-                }
-            }
-            else
-            {
-                if (refText.endsWithNewline)
-                {
-                    writeln(refFileName, " ends with a newline, but ", outFileName, " does not.");
-                    return 1;
-                }
-            }
         }
 
     foreach (entry; dirEntries("expected_failures", "*.d", SpanMode.shallow))
@@ -88,16 +65,3 @@ int main()
     writeln("All tests succeeded.");
     return 0;
 }
-
-bool endsWithNewline(string text) pure
-{
-    // Same criteria as https://dlang.org/phobos/std_string.html#.lineSplitter
-    return
-        text.endsWith('\n') ||
-        text.endsWith('\r') ||
-        text.endsWith(lineSep) ||
-        text.endsWith(paraSep) ||
-        text.endsWith('\u0085') ||
-        text.endsWith('\v') ||
-        text.endsWith('\f');
-}