Add calculation steps to output, bump version to v0.1.0v0.1.0

Amp-Thread-ID: https://ampcode.com/threads/T-3883950c-6af3-4944-8596-7a40341c9c58
Co-authored-by: Amp <amp@ampcode.com>

3 files changed, 31 insertions, 10 deletions

diff --git a/internal/calculator/calculator.go b/internal/calculator/calculator.go
index ee1ff6f..fdca99b 100644
--- a/internal/calculator/calculator.go
+++ b/internal/calculator/calculator.go
@@ -39,7 +39,11 @@ func parseXPercentOfY(input string) (string, bool) {
 	base, _ := strconv.ParseFloat(matches[2], 64)
 
 	result := (percent / 100.0) * base
-	return fmt.Sprintf("%.2f%% of %.2f = %.2f", percent, base, result), true
+
+	output := fmt.Sprintf("%.2f%% of %.2f = %.2f\n", percent, base, result)
+	output += fmt.Sprintf("  Steps: (%.2f / 100) * %.2f = %.2f * %.2f = %.2f", percent, base, percent/100.0, base, result)
+
+	return output, true
 }
 
 func parseXIsWhatPercentOfY(input string) (string, bool) {
@@ -58,7 +62,11 @@ func parseXIsWhatPercentOfY(input string) (string, bool) {
 	}
 
 	percent := (part / whole) * 100.0
-	return fmt.Sprintf("%.2f is %.2f%% of %.2f", part, percent, whole), true
+
+	output := fmt.Sprintf("%.2f is %.2f%% of %.2f\n", part, percent, whole)
+	output += fmt.Sprintf("  Steps: (%.2f / %.2f) * 100 = %.2f * 100 = %.2f%%", part, whole, part/whole, percent)
+
+	return output, true
 }
 
 func parseXIsYPercentOfWhat(input string) (string, bool) {
@@ -77,5 +85,9 @@ func parseXIsYPercentOfWhat(input string) (string, bool) {
 	}
 
 	whole := (part / percent) * 100.0
-	return fmt.Sprintf("%.2f is %.2f%% of %.2f", part, percent, whole), true
+
+	output := fmt.Sprintf("%.2f is %.2f%% of %.2f\n", part, percent, whole)
+	output += fmt.Sprintf("  Steps: (%.2f / %.2f) * 100 = %.2f * 100 = %.2f", part, percent, part/percent, whole)
+
+	return output, true
 }
diff --git a/internal/calculator/calculator_test.go b/internal/calculator/calculator_test.go
index defbd13..2724d71 100644
--- a/internal/calculator/calculator_test.go
+++ b/internal/calculator/calculator_test.go
@@ -49,8 +49,11 @@ func TestParseXPercentOfY(t *testing.T) {
 			if err != nil {
 				t.Fatalf("Parse(%q) returned error: %v", tt.input, err)
 			}
-			if result != tt.expected {
-				t.Errorf("Parse(%q) = %q, expected %q", tt.input, result, tt.expected)
+			if !strings.HasPrefix(result, tt.expected) {
+				t.Errorf("Parse(%q) = %q, expected to start with %q", tt.input, result, tt.expected)
+			}
+			if !strings.Contains(result, "Steps:") {
+				t.Errorf("Parse(%q) = %q, expected to contain calculation steps", tt.input, result)
 			}
 		})
 	}
@@ -95,8 +98,11 @@ func TestParseXIsWhatPercentOfY(t *testing.T) {
 			if err != nil {
 				t.Fatalf("Parse(%q) returned error: %v", tt.input, err)
 			}
-			if result != tt.expected {
-				t.Errorf("Parse(%q) = %q, expected %q", tt.input, result, tt.expected)
+			if !strings.HasPrefix(result, tt.expected) {
+				t.Errorf("Parse(%q) = %q, expected to start with %q", tt.input, result, tt.expected)
+			}
+			if !strings.Contains(result, "Steps:") {
+				t.Errorf("Parse(%q) = %q, expected to contain calculation steps", tt.input, result)
 			}
 		})
 	}
@@ -141,8 +147,11 @@ func TestParseXIsYPercentOfWhat(t *testing.T) {
 			if err != nil {
 				t.Fatalf("Parse(%q) returned error: %v", tt.input, err)
 			}
-			if result != tt.expected {
-				t.Errorf("Parse(%q) = %q, expected %q", tt.input, result, tt.expected)
+			if !strings.HasPrefix(result, tt.expected) {
+				t.Errorf("Parse(%q) = %q, expected to start with %q", tt.input, result, tt.expected)
+			}
+			if !strings.Contains(result, "Steps:") {
+				t.Errorf("Parse(%q) = %q, expected to contain calculation steps", tt.input, result)
 			}
 		})
 	}
diff --git a/internal/version.go b/internal/version.go
index 3eeaed5..8826dc9 100644
--- a/internal/version.go
+++ b/internal/version.go
@@ -1,3 +1,3 @@
 package internal
 
-const Version = "v0.0.1"
+const Version = "v0.1.0"