gitbook: Add summary modifier `deleteByPath`

3 files changed, 237 insertions, 0 deletions

diff --git a/packages/gitbook/src/modifiers/summary/__tests__/deleteByPath.js b/packages/gitbook/src/modifiers/summary/__tests__/deleteByPath.js
new file mode 100644
index 0000000..2557210
--- /dev/null
+++ b/packages/gitbook/src/modifiers/summary/__tests__/deleteByPath.js
@@ -0,0 +1,170 @@
+const expect = require('expect');
+const Summary = require('../../../models/summary');
+
+describe('deleteByPath', () => {
+    const deleteByPath = require('../deleteByPath');
+
+    const summary = Summary.createFromParts([
+        {
+            articles: [
+                {
+                    title: 'Intro',
+                    path: 'README.md'
+                }
+            ]
+        },
+        {
+            title: 'Part',
+            articles: [
+                {
+                    title: '1',
+                    path: ''
+                },
+                {
+                    title: '2',
+                    path: '2/README.md',
+                    articles: [
+                        {
+                            title: '2a',
+                            path: '2/1.md'
+                        },
+                        {
+                            title: '2b',
+                            path: '2/1.md#anchor'
+                        }
+                    ]
+                }
+            ]
+        }
+    ]);
+
+    it('should remove a single article', () => {
+        const newSummary = deleteByPath(summary, 'README.md');
+        expectParts(newSummary, [
+            {
+                articles: []
+            },
+            {
+                title: 'Part',
+                articles: [
+                    {
+                        title: '1',
+                        path: ''
+                    },
+                    {
+                        title: '2',
+                        path: '2/README.md',
+                        articles: [
+                            {
+                                title: '2a',
+                                path: '2/1.md'
+                            },
+                            {
+                                title: '2b',
+                                path: '2/1.md#anchor'
+                            }
+                        ]
+                    }
+                ]
+            }
+        ]);
+    });
+
+    it('should handle anchors', () => {
+        const newSummary = deleteByPath(summary, '2/1.md');
+        expectParts(newSummary, [
+            {
+                articles: [
+                    {
+                        title: 'Intro',
+                        path: 'README.md'
+                    }
+                ]
+            },
+            {
+                title: 'Part',
+                articles: [
+                    {
+                        title: '1',
+                        path: ''
+                    },
+                    {
+                        title: '2',
+                        path: '2/README.md',
+                        articles: []
+                    }
+                ]
+            }
+        ]);
+    });
+
+    it('should handle dirs', () => {
+        const newSummary = deleteByPath(summary, '2/');
+        expectParts(newSummary, [
+            {
+                articles: [
+                    {
+                        title: 'Intro',
+                        path: 'README.md'
+                    }
+                ]
+            },
+            {
+                title: 'Part',
+                articles: [
+                    {
+                        title: '1',
+                        path: ''
+                    }
+                ]
+            }
+        ]);
+    });
+
+    it('should not delete descendants that don\'t match', () => {
+        const newSummary = deleteByPath(summary, '2/README.md');
+        expectParts(newSummary, [
+            {
+                articles: [
+                    {
+                        title: 'Intro',
+                        path: 'README.md'
+                    }
+                ]
+            },
+            {
+                title: 'Part',
+                articles: [
+                    {
+                        title: '1',
+                        path: ''
+                    },
+                    {
+                        title: '2',
+                        // Unlink
+                        articles: [
+                            {
+                                title: '2a',
+                                path: '2/1.md'
+                            },
+                            {
+                                title: '2b',
+                                path: '2/1.md#anchor'
+                            }
+                        ]
+                    }
+                ]
+            }
+        ]);
+    });
+});
+
+function expectParts(summary, expectedParts) {
+    const expectedSummary = Summary.createFromParts(expectedParts);
+    expect(
+        summary.toJS().parts
+    ).toEqual(
+        expectedSummary.toJS().parts
+    );
+}
+
diff --git a/packages/gitbook/src/modifiers/summary/deleteByPath.js b/packages/gitbook/src/modifiers/summary/deleteByPath.js
new file mode 100644
index 0000000..3ab6c92
--- /dev/null
+++ b/packages/gitbook/src/modifiers/summary/deleteByPath.js
@@ -0,0 +1,66 @@
+const Path = require('path');
+
+/**
+ Delete all articles that point to a file under the given path, unless
+ some of their children do not share that same path.
+
+ @param {Summary} summary
+ @param {String} path Can be a file path or directory path
+ @return {Summary}
+*/
+function deleteByPath(summary, path) {
+    const parts = summary.getParts()
+        .map((part) => {
+            const articles = deleteArticlesByPath(part.getArticles(), path);
+            return part.merge({ articles });
+        });
+
+    return summary.merge({ parts });
+}
+
+/**
+ Same as `deleteByPath` but for a list of articles.
+
+ @param {List<Article>} articles
+ @param {String} path
+ @return {List<Article}
+ */
+function deleteArticlesByPath(articles, path) {
+    return articles
+        // Delete leaf articles first
+        .map(article => article.merge({
+            articles: deleteArticlesByPath(article.articles, path)
+        }))
+        // Then delete top level articles if they don't have any descendant left.
+        .filterNot(
+            article => article.getArticles().isEmpty() && isInside(article, path)
+        )
+        // Unlink those left
+        .map(article => isInside(article, path) ? article.merge({ ref: '' }) : article);
+}
+
+/**
+ @param {Article} article
+ @param {String} potentialParent
+ @return {Boolean} True if path match the parent path, or if path is inside parent path
+ */
+function isInside(article, potentialParent) {
+    // For inside-directory checking, we want to allow trailing slashes, so normalize.
+    const path = stripTrailingSep(article.getPath() || '');
+    potentialParent = stripTrailingSep(potentialParent);
+
+    return path.lastIndexOf(potentialParent, 0) === 0 &&
+        (
+            path[potentialParent.length] === Path.sep ||
+            path[potentialParent.length] === undefined
+        );
+}
+
+function stripTrailingSep(path) {
+    if (path[path.length - 1] === Path.sep) {
+        return path.slice(0, -1);
+    }
+    return path;
+}
+
+module.exports = deleteByPath;
diff --git a/packages/gitbook/src/modifiers/summary/index.js b/packages/gitbook/src/modifiers/summary/index.js
index cb8e8f9..28ec625 100644
--- a/packages/gitbook/src/modifiers/summary/index.js
+++ b/packages/gitbook/src/modifiers/summary/index.js
@@ -9,6 +9,7 @@ module.exports = {
     unshiftArticle:   require('./unshiftArticle'),
     editArticleTitle: require('./editArticleTitle'),
     editArticleRef:   require('./editArticleRef'),
+    deleteByPath:     require('./deleteByPath'),
     // Parts
     insertPart:       require('./insertPart'),
     removePart:       require('./removePart'),