paragraph: add support for page break before format property (#7)

src/file/paragraph/formatting/page-break.spec.ts

@@ -1,7 +1,7 @@
 import { assert } from "chai";
 
 import { Utility } from "../../../tests/utility";
-import { PageBreak } from "./page-break";
+import { PageBreak, PageBreakBefore } from "./page-break";
 
 describe("PageBreak", () => {
     let pageBreak: PageBreak;
@@ -30,3 +30,11 @@ describe("PageBreak", () => {
         });
     });
 });
+
+describe("PageBreakBefore", () => {
+    it("should create page break before", () => {
+        const pageBreakBefore = new PageBreakBefore();
+        const newJson = Utility.jsonify(pageBreakBefore);
+        assert.equal(newJson.rootKey, "w:pageBreakBefore");
+    });
+});

src/file/paragraph/formatting/page-break.ts

@@ -19,3 +19,12 @@ export class PageBreak extends Run {
         this.root.push(new Break());
     }
 }
+
+/**
+ * Add page break before the paragraph if there is no one added before.
+ */
+export class PageBreakBefore extends XmlComponent {
+    constructor() {
+        super("w:pageBreakBefore");
+    }
+}

src/file/paragraph/paragraph.spec.ts

@@ -161,6 +161,22 @@ describe("Paragraph", () => {
         });
     });
 
+    describe("#pageBreakBefore()", () => {
+        it("should add page break before to JSON", () => {
+            paragraph.pageBreakBefore();
+            const tree = new Formatter().format(paragraph);
+            expect(tree).to.deep.equal({
+                "w:p": [
+                    {
+                        "w:pPr": [{
+                            "w:pageBreakBefore": []
+                        }],
+                    }
+                ],
+            });
+        });
+    });
+
     describe("#bullet()", () => {
         it("should add list paragraph style to JSON", () => {
             paragraph.bullet();

src/file/paragraph/paragraph.ts

@@ -8,7 +8,7 @@ import { Alignment } from "./formatting/alignment";
 import { ThematicBreak } from "./formatting/border";
 import { Indent } from "./formatting/indent";
 import { KeepLines, KeepNext } from "./formatting/keep";
-import { PageBreak } from "./formatting/page-break";
+import { PageBreak, PageBreakBefore } from "./formatting/page-break";
 import { ISpacingProperties, Spacing } from "./formatting/spacing";
 import { Style } from "./formatting/style";
 import { CenterTabStop, LeftTabStop, MaxRightTabStop, RightTabStop } from "./formatting/tab-stop";
@@ -104,6 +104,11 @@ export class Paragraph extends XmlComponent {
         return this;
     }
 
+    public pageBreakBefore(): Paragraph {
+        this.properties.push(new PageBreakBefore());
+        return this;
+    }
+
     public maxRightTabStop(): Paragraph {
         this.properties.push(new MaxRightTabStop());
         return this;