Initial data commit

Task/Middle-three-digits/Go/middle-three-digits-1.go

@@ -0,0 +1,26 @@
+package m3
+
+import (
+    "errors"
+    "strconv"
+)
+
+var (
+    ErrorLT3  = errors.New("N of at least three digits required.")
+    ErrorEven = errors.New("N with odd number of digits required.")
+)
+
+func Digits(i int) (string, error) {
+    if i < 0 {
+        i = -i
+    }
+    if i < 100 {
+        return "", ErrorLT3
+    }
+    s := strconv.Itoa(i)
+    if len(s)%2 == 0 {
+        return "", ErrorEven
+    }
+    m := len(s) / 2
+    return s[m-1 : m+2], nil
+}

Task/Middle-three-digits/Go/middle-three-digits-2.go

@@ -0,0 +1,59 @@
+package m3_test
+
+import (
+    "testing"
+
+    "m3"
+)
+
+func TestPassing(t *testing.T) {
+    type s struct {
+        i int
+        m string
+    }
+    tcs := []s{
+        {123, "123"},
+        {12345, "234"},
+        {1234567, "345"},
+        {987654321, "654"},
+        {10001, "000"},
+        {-10001, "000"},
+    }
+    for _, tc := range tcs {
+        m, err := m3.Digits(tc.i)
+        if err != nil {
+            t.Fatalf("d(%d) returned %q.", tc.i, err)
+        }
+        if m != tc.m {
+            t.Fatalf("d(%d) expected %q, got %q.", tc.i, tc.m, m)
+        }
+        t.Logf("d(%d) = %q.", tc.i, m)
+    }
+}
+
+func TestFailing(t *testing.T) {
+    type s struct {
+        i   int
+        err error
+    }
+    tcs := []s{
+        {1, m3.ErrorLT3},
+        {2, m3.ErrorLT3},
+        {-1, m3.ErrorLT3},
+        {-10, m3.ErrorLT3},
+        {2002, m3.ErrorEven},
+        {-2002, m3.ErrorEven},
+        {0, m3.ErrorLT3},
+    }
+    for _, tc := range tcs {
+        m, err := m3.Digits(tc.i)
+        if err == nil {
+            t.Fatal("d(%d) expected error %q, got non-error %q.",
+                tc.i, tc.err, m)
+        }
+        if err != tc.err {
+            t.Fatal("d(d) expected error %q, got %q", tc.i, tc.err, err)
+        }
+        t.Logf("d(%d) returns %q", tc.i, err)
+    }
+}