SharingGRDBTestSupport with assertQuery

Package.swift

@@ -19,6 +19,10 @@ let package = Package(
       name: "SharingGRDBCore",
       targets: ["SharingGRDBCore"]
     ),
+    .library(
+      name: "SharingGRDBTestSupport",
+      targets: ["SharingGRDBTestSupport"]
+    ),
     .library(
       name: "StructuredQueriesGRDB",
       targets: ["StructuredQueriesGRDB"]
@@ -29,10 +33,12 @@ let package = Package(
     ),
   ],
   dependencies: [
+    .package(url: "https://github.com/pointfreeco/swift-custom-dump", from: "1.3.3"),
     .package(url: "https://github.com/groue/GRDB.swift", from: "7.4.0"),
     .package(url: "https://github.com/pointfreeco/swift-dependencies", from: "1.9.0"),
     .package(url: "https://github.com/pointfreeco/xctest-dynamic-overlay", from: "1.5.0"),
     .package(url: "https://github.com/pointfreeco/swift-sharing", from: "2.3.0"),
+    .package(url: "https://github.com/pointfreeco/swift-snapshot-testing", from: "1.18.4"),
     .package(url: "https://github.com/pointfreeco/swift-structured-queries", from: "0.13.0"),
   ],
   targets: [
@@ -55,10 +61,20 @@ let package = Package(
       name: "SharingGRDBTests",
       dependencies: [
         "SharingGRDB",
+        "SharingGRDBTestSupport",
         .product(name: "DependenciesTestSupport", package: "swift-dependencies"),
         .product(name: "StructuredQueries", package: "swift-structured-queries"),
       ]
     ),
+    .target(
+      name: "SharingGRDBTestSupport",
+      dependencies: [
+        "SharingGRDB",
+        .product(name: "CustomDump", package: "swift-custom-dump"),
+        .product(name: "InlineSnapshotTesting", package: "swift-snapshot-testing"),
+        .product(name: "StructuredQueriesTestSupport", package: "swift-structured-queries"),
+      ]
+    ),
     .target(
       name: "StructuredQueriesGRDBCore",
       dependencies: [

Sources/SharingGRDBTestSupport/AssertQuery.swift

@@ -0,0 +1,271 @@
+import CustomDump
+import Dependencies
+import Foundation
+import GRDB
+import InlineSnapshotTesting
+import StructuredQueriesCore
+import StructuredQueriesGRDBCore
+import StructuredQueriesTestSupport
+
+/// An end-to-end snapshot testing helper for database content.
+///
+/// This helper can be used to generate snapshots of both the given query and the results of the
+/// query decoded back into Swift.
+///
+/// ```swift
+/// assertQuery(
+///   Reminder.select(\.title).order(by: \.title)
+/// } results: {
+///   """
+///   ┌────────────────────────────┐
+///   │ "Buy concert tickets"      │
+///   │ "Call accountant"          │
+///   │ "Doctor appointment"       │
+///   │ "Get laundry"              │
+///   │ "Groceries"                │
+///   │ "Haircut"                  │
+///   │ "Pick up kids from school" │
+///   │ "Send weekly emails"       │
+///   │ "Take a walk"              │
+///   │ "Take out trash"           │
+///   └────────────────────────────┘
+///   """
+/// }
+/// ```
+///
+/// - Parameters:
+///   - includeSQL: Whether to snapshot the SQL fragment in addition to the results.
+///   - query: A statement.
+///   - database: The database to read from. A value of `nil` will use
+///     `@Dependency(\.defaultDatabase)`.
+///   - sql: A snapshot of the SQL produced by the statement.
+///   - results: A snapshot of the results.
+///     to `1` for invoking this helper directly, but if you write a wrapper function that automates
+///     the `execute` trailing closure, you should pass `0` instead.
+///   - fileID: The source `#fileID` associated with the assertion.
+///   - filePath: The source `#filePath` associated with the assertion.
+///   - function: The source `#function` associated with the assertion
+///   - line: The source `#line` associated with the assertion.
+///   - column: The source `#column` associated with the assertion.
+@available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
+@_disfavoredOverload
+public func assertQuery<each V: QueryRepresentable, S: StructuredQueriesCore.Statement<(repeat each V)>>(
+  includeSQL: Bool = false,
+  _ query: S,
+  database: (any DatabaseReader)? = nil,
+  sql: (() -> String)? = nil,
+  results: (() -> String)? = nil,
+  fileID: StaticString = #fileID,
+  filePath: StaticString = #filePath,
+  function: StaticString = #function,
+  line: UInt = #line,
+  column: UInt = #column
+) {
+  if includeSQL {
+    assertInlineSnapshot(
+      of: query,
+      as: .sql,
+      message: "Query did not match",
+      syntaxDescriptor: InlineSnapshotSyntaxDescriptor(
+        trailingClosureLabel: "sql",
+        trailingClosureOffset: 0
+      ),
+      matches: sql,
+      fileID: fileID,
+      file: filePath,
+      function: function,
+      line: line,
+      column: column
+    )
+  }
+  do {
+    @Dependency(\.defaultDatabase) var defaultDatabase
+    let rows = try (database ?? defaultDatabase).read { try query.fetchAll($0) }
+    var table = ""
+    printTable(rows, to: &table)
+    if !table.isEmpty {
+      assertInlineSnapshot(
+        of: table,
+        as: .lines,
+        message: "Results did not match",
+        syntaxDescriptor: InlineSnapshotSyntaxDescriptor(
+          trailingClosureLabel: "results",
+          trailingClosureOffset: includeSQL ? 1 : 0
+        ),
+        matches: includeSQL ? results : sql,
+        fileID: fileID,
+        file: filePath,
+        function: function,
+        line: line,
+        column: column
+      )
+    } else if results != nil {
+      assertInlineSnapshot(
+        of: table,
+        as: .lines,
+        message: "Results expected to be empty",
+        syntaxDescriptor: InlineSnapshotSyntaxDescriptor(
+          trailingClosureLabel: "results",
+          trailingClosureOffset: includeSQL ? 1 : 0
+        ),
+        matches: includeSQL ? results : sql,
+        fileID: fileID,
+        file: filePath,
+        function: function,
+        line: line,
+        column: column
+      )
+    }
+  } catch {
+    assertInlineSnapshot(
+      of: error.localizedDescription,
+      as: .lines,
+      message: "Results did not match",
+      syntaxDescriptor: InlineSnapshotSyntaxDescriptor(
+        trailingClosureLabel: "results",
+        trailingClosureOffset: includeSQL ? 1 : 0
+      ),
+      matches: includeSQL ? results : sql,
+      fileID: fileID,
+      file: filePath,
+      function: function,
+      line: line,
+      column: column
+    )
+  }
+}
+
+/// An end-to-end snapshot testing helper for database content.
+///
+/// This helper can be used to generate snapshots of both the given query and the results of the
+/// query decoded back into Swift.
+///
+/// ```swift
+/// assertQuery(
+///   Reminder.select(\.title).order(by: \.title)
+/// } results: {
+///   """
+///   ┌────────────────────────────┐
+///   │ "Buy concert tickets"      │
+///   │ "Call accountant"          │
+///   │ "Doctor appointment"       │
+///   │ "Get laundry"              │
+///   │ "Groceries"                │
+///   │ "Haircut"                  │
+///   │ "Pick up kids from school" │
+///   │ "Send weekly emails"       │
+///   │ "Take a walk"              │
+///   │ "Take out trash"           │
+///   └────────────────────────────┘
+///   """
+/// }
+/// ```
+///
+/// - Parameters:
+///   - includeSQL: Whether to snapshot the SQL fragment in addition to the results.
+///   - query: A statement.
+///   - sql: A snapshot of the SQL produced by the statement.
+///   - database: The database to read from. A value of `nil` will use
+///     `@Dependency(\.defaultDatabase)`.
+///   - results: A snapshot of the results.
+///     to `1` for invoking this helper directly, but if you write a wrapper function that automates
+///     the `execute` trailing closure, you should pass `0` instead.
+///   - fileID: The source `#fileID` associated with the assertion.
+///   - filePath: The source `#filePath` associated with the assertion.
+///   - function: The source `#function` associated with the assertion
+///   - line: The source `#line` associated with the assertion.
+///   - column: The source `#column` associated with the assertion.
+@available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
+public func assertQuery<S: SelectStatement, each J: StructuredQueriesCore.Table>(
+  includeSQL: Bool = false,
+  _ query: S,
+  database: (any DatabaseReader)? = nil,
+  sql: (() -> String)? = nil,
+  results: (() -> String)? = nil,
+  fileID: StaticString = #fileID,
+  filePath: StaticString = #filePath,
+  function: StaticString = #function,
+  line: UInt = #line,
+  column: UInt = #column
+) where S.QueryValue == (), S.Joins == (repeat each J) {
+  assertQuery(
+    includeSQL: includeSQL,
+    query.selectStar(),
+    database: database,
+    sql: sql,
+    results: results,
+    fileID: fileID,
+    filePath: filePath,
+    function: function,
+    line: line,
+    column: column
+  )
+}
+
+private func printTable<each C>(_ rows: [(repeat each C)], to output: inout some TextOutputStream) {
+  var maxColumnSpan: [Int] = []
+  var hasMultiLineRows = false
+  for _ in repeat (each C).self {
+    maxColumnSpan.append(0)
+  }
+  var table: [([[Substring]], maxRowSpan: Int)] = []
+  for row in rows {
+    var columns: [[Substring]] = []
+    var index = 0
+    var maxRowSpan = 0
+    for column in repeat each row {
+      defer { index += 1 }
+      var cell = ""
+      customDump(column, to: &cell)
+      let lines = cell.split(separator: "\n")
+      hasMultiLineRows = hasMultiLineRows || lines.count > 1
+      maxRowSpan = max(maxRowSpan, lines.count)
+      maxColumnSpan[index] = max(maxColumnSpan[index], lines.map(\.count).max() ?? 0)
+      columns.append(lines)
+    }
+    table.append((columns, maxRowSpan))
+  }
+  guard !table.isEmpty else { return }
+  output.write("┌─")
+  output.write(
+    maxColumnSpan
+      .map { String(repeating: "─", count: $0) }
+      .joined(separator: "─┬─")
+  )
+  output.write("─┐\n")
+  for (offset, rowAndMaxRowSpan) in table.enumerated() {
+    let (row, maxRowSpan) = rowAndMaxRowSpan
+    for rowOffset in 0..<maxRowSpan {
+      output.write("│ ")
+      var line: [String] = []
+      for (columns, maxColumnSpan) in zip(row, maxColumnSpan) {
+        if columns.count <= rowOffset {
+          line.append(String(repeating: " ", count: maxColumnSpan))
+        } else {
+          line.append(
+            columns[rowOffset]
+              + String(repeating: " ", count: maxColumnSpan - columns[rowOffset].count)
+          )
+        }
+      }
+      output.write(line.joined(separator: " │ "))
+      output.write(" │\n")
+    }
+    if hasMultiLineRows, offset != table.count - 1 {
+      output.write("├─")
+      output.write(
+        maxColumnSpan
+          .map { String(repeating: "─", count: $0) }
+          .joined(separator: "─┼─")
+      )
+      output.write("─┤\n")
+    }
+  }
+  output.write("└─")
+  output.write(
+    maxColumnSpan
+      .map { String(repeating: "─", count: $0) }
+      .joined(separator: "─┴─")
+  )
+  output.write("─┘")
+}