Implement readInto and read(n)

tests/test_inputs.nim

@@ -1,23 +1,121 @@
 {.used.}
 
 import
-  os, unittest, strutils, stew/ranges/ptr_arith,
-  ../faststreams
+  os, unittest, strutils, random,
+  stew/ranges/ptr_arith, testutils,
+  ../faststreams, ../faststreams/textio
 
-suite "input stream":
-  test "empty input":
+setCurrentDir getAppDir()
+
+proc bytes(s: string): seq[byte] =
+  result = newSeqOfCap[byte](s.len)
+  for c in s: result.add byte(c)
+
+proc str(bytes: openarray[byte]): string =
+  result = newStringOfCap(bytes.len)
+  for b in bytes:
+    result.add b.char
+
+proc countLines(s: InputStream): Natural =
+  for s in lines(s):
+    inc result
+
+const
+  asciiTableFile = "files" / "ascii_table.txt"
+  asciiTableContents = slurp(asciiTableFile)
+
+procSuite "input stream":
+  template emptyInputTests(suiteName, setupCode: untyped) =
+    suite suiteName & " empty inputs":
+      setup setupCode
+
+      test "input is not readable with read":
+        check not input.readable
+        expect Defect:
+          echo "This read should not complete: ", input.read
+
+      test "input is not readable with read(n)":
+        check not input.readable(10)
+        expect Defect:
+          echo "This read should not complete: ", input.read(10)
+
+      test "next returns none":
+        check input.next.isNone
+
+  emptyInputTests "unsafeMemoryInput":
     var str = ""
-    var i = unsafeMemoryInput(str)
+    var input = unsafeMemoryInput(str)
 
-    check:
-      i.readable == false
-      i.next.isNone
+  emptyInputTests "fileInput":
+    var input = memFileInput("files" / "empty_file")
 
-    expect Defect:
-      echo i.read
+  emptyInputTests "memFileInput":
+    var input = fileInput("files" / "empty_file")
+
+  template asciiTableFileTest(name: string, body: untyped) =
+    test name & " of ascii table with regular pageSize":
+      var input {.inject.} = fileInput(asciiTableFile)
+      try:
+        body
+      finally:
+        close input
+
+    test name & " of ascii table with pageSize = 10":
+      var input {.inject.} = fileInput(asciiTableFile, pageSize = 10)
+      try:
+        body
+      finally:
+        close input
+
+    test name & " of ascii table with pageSize = 1":
+      var input {.inject.} = fileInput(asciiTableFile, pageSize = 1)
+      try:
+        body
+      finally:
+        close input
+
+  asciiTableFileTest "count lines":
+    check countLines(input) == 34
+
+  asciiTableFileTest "mixed read types":
+    randomize(10000)
+
+    var fileContents = ""
+
+    while true:
+      let r = rand(100)
+      if r < 20:
+        let readSize = 1 + rand(10)
+
+        var buf = newSeq[byte](readSize)
+        let bytesRead = input.readIntoEx(buf)
+        fileContents.add buf.toOpenArray(0, bytesRead - 1).str
+
+        if bytesRead < buf.len:
+          break
+
+      elif r < 50:
+        let readSize = 6 + rand(10)
+
+        if input.readable(readSize):
+          fileContents.add input.read(readSize).str
+        else:
+          while input.readable:
+            fileContents.add input.read.char
+          break
+
+      else:
+        if input.readable:
+          fileContents.add input.read.char
+
+      # You can uncomment this to get earlier failure in the test:
+      when false:
+        require fileContents == asciiTableContents[0 ..< fileContents.len]
+
+    check fileContents == asciiTableContents
 
   test "missing file input":
-    const fileName = "there-is-no-such-faststreams-file-1"
+    const fileName = "there-is-no-such-faststreams-file"
 
     check not fileExists(fileName)
     expect CatchableError: discard fileInput(fileName)