Improve detection of separator row.

Related #1

Author: darkriszty

CHANGELOG.md

@@ -4,6 +4,7 @@ All notable changes to the `markdowntableprettify` extension will be documented
 The format is based on [Keep a Changelog](http://keepachangelog.com/) and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
+- Fixed issue #1 by improving the detection of header separator to avoid unintended table formatting failures.
 
 ## 1.0.0 - 2017-04-03
 ### Added

demonstration.md

@@ -16,7 +16,7 @@ int|32|Integer|
 
 Create missing ending table border if the beginning already has a border:
 |Primitive Type|Size(bit)|Wrapper
-|-|-|-|
+|-|-|-
 |short|16|Short
 |int|32|Integer
 

src/tableFactory.ts

@@ -14,40 +14,59 @@ export class TableFactory implements ITableFactory {
             .map(l => l.split("|"))
             .filter(arr => !(arr.length == 1 && arr[0] == ""));
 
+        if (!TableValidator.rowAndColumnSizeValid(rows))
+            return null;
+
         // remove the separator line from second line
-        const rowsWithoutSeparator = TableValidator.containsHeaderSeparator(rows)
+        const rowsWithoutSeparator = TableValidator.hasValidSeparators(rows)
             ? rows.filter((v, i) => i != 1) // remove the separator line from second line
             : null;
 
-        if (!TableValidator.areValidRows(rowsWithoutSeparator))
-            return null;
-
-        return new Table(rowsWithoutSeparator);
+        return rowsWithoutSeparator != null ? new Table(rowsWithoutSeparator) : null;
     }
 }
 
 class TableValidator {
-    public static containsHeaderSeparator(rawRows: string[][]): boolean {
+    public static rowAndColumnSizeValid(rawRows: string[][]): boolean {
+        return !!rawRows && 
+                rawRows.length > 2 && // at least two rows are required besides the separator
+                rawRows[0].length > 1 && // at least two columns are required
+                rawRows.every(r => r.length == rawRows[0].length); // all rows of a column must match the length of the first row of that column
+    }
+
+    public static hasValidSeparators(rawRows: string[][]): boolean {
         if (!rawRows || rawRows.length < 1 || !rawRows[1])
             return false;
+
+        // if all columns are dashes, then it is valid
         const secondRow = rawRows[1];
-        return secondRow.every((v, i) => this.isSeparator(v, i == 0 || i == secondRow.length - 1));
+        const allCellsDash = secondRow.every(cell => this.composedOfDashes(cell));
+        if (allCellsDash)
+            return true;
+
+        // now it can only be valid of the table starts or ends with a border and the middle columns are dashes
+        return this.allDashesWithBorder(secondRow);
     }
 
-    private static isSeparator(cellValue: string, isFirstOrLast: boolean): boolean {
-        if (cellValue.trim() == "-")
-            return true;
-        // If the first or last column is empty then it still can be a header containing separator, 
-        // for example table starting or ending with borders ("|") would produce this.
-        if (cellValue.trim() == "" && isFirstOrLast)
+    private static composedOfDashes(cellValue: string): boolean {
+        const trimmedSpace = cellValue.trim();
+        const firstDash = trimmedSpace.replace(/(?!^)-/g, "");
+        if (firstDash === "-")
             return true;
         return false;
     }
 
-    public static areValidRows(rawRows: string[][]): boolean {
-        return !!rawRows && 
-                rawRows.length > 1 && // at least two rows are required
-                rawRows[0].length > 1 && // at least two columns are required
-                rawRows.every(r => r.length == rawRows[0].length); // all rows of a column must match the length of the first row of that column
+    private static allDashesWithBorder(secondRow: string[]): boolean {
+        const hasStartingBorder = secondRow.length >= 3 && secondRow[0].trim() === "";
+        const hasEndingBorder = secondRow.length >= 3 && secondRow[secondRow.length - 1].trim() === "";
+
+        let startIndex = hasStartingBorder ? 1 : 0;
+        let endIndex = hasEndingBorder ? secondRow.length - 2 : secondRow.length - 1;
+
+        const middleColumns = secondRow.filter((v, i) => i >= startIndex && i <= endIndex);
+        const middleColumnsAllDash = middleColumns.every(cell => this.composedOfDashes(cell));
+        if (middleColumnsAllDash && (hasStartingBorder || hasEndingBorder))
+            return true;
+        return false;
     }
 }

test/tableFactory.test.ts

@@ -67,4 +67,53 @@ suite("TableFactory tests", () => {
         assert.equal(true, table != null);
         assert.equal(true, (table as ITable) != null);
     });
+
+    test("create() two column header with longer separator and a row table instance created", () => {
+        const text = `header 1 | header 2
+                      ----|----
+                      value 1 | value 2`;
+        const factory = new TableFactory();
+        const table = factory.create(text);
+        assert.equal(true, table != null);
+        assert.equal(true, (table as ITable) != null);
+    });
+
+    test("create() table with left border and valid separator a table instance created", () => {
+        const text = `|header 1 | header 2
+                      |-|----
+                      |value 1 | value 2`;
+        const factory = new TableFactory();
+        const table = factory.create(text);
+        assert.equal(true, table != null);
+        assert.equal(true, (table as ITable) != null);
+    });
+
+    test("create() table with right border and valid separator a table instance created", () => {
+        const text = `header 1 | header 2|
+                      ---|----|
+                      value 1 | value 2|`;
+        const factory = new TableFactory();
+        const table = factory.create(text);
+        assert.equal(true, table != null);
+        assert.equal(true, (table as ITable) != null);
+    });
+
+    test("create() table with both borders and valid separator a table instance created", () => {
+        const text = `|header 1 | header 2|
+                      |---|---|
+                      |value 1 | value 2|`;
+        const factory = new TableFactory();
+        const table = factory.create(text);
+        assert.equal(true, table != null);
+        assert.equal(true, (table as ITable) != null);
+    });
+
+    test("create() two column header with invalid separator null table returned", () => {
+        const text = `header 1 | header 2
+                      |
+                      value 1 | value 2`;
+        const factory = new TableFactory();
+        const table = factory.create(text);
+        assert.equal(table, null);
+    });
 });