set the param type based on the default value

Check if the type is specified or not, if not, infer it from the
default value.

This commit fixes a bug where the param type is set to the default type without
checking if default type is specified or not.

pkg/apis/pipeline/v1beta1/param_types.go

@@ -57,7 +57,17 @@ func (pp *ParamSpec) SetDefaults(ctx context.Context) {
 	if pp != nil && pp.Type == "" {
 		if pp.Default != nil {
 			// propagate the parsed ArrayOrString's type to the parent ParamSpec's type
-			pp.Type = pp.Default.Type
+			if pp.Default.Type != "" {
+				// propagate the default type if specified
+				pp.Type = pp.Default.Type
+			} else {
+				// determine the type based on the array or string values when default value is specified but not the type
+				if pp.Default.ArrayVal != nil {
+					pp.Type = ParamTypeArray
+				} else {
+					pp.Type = ParamTypeString
+				}
+			}
 		} else {
 			// ParamTypeString is the default value (when no type can be inferred from the default value)
 			pp.Type = ParamTypeString

pkg/apis/pipeline/v1beta1/param_types_test.go

@@ -42,29 +42,52 @@ func TestParamSpec_SetDefaults(t *testing.T) {
 			Type: v1beta1.ParamTypeString,
 		},
 	}, {
-		name: "inferred type from default value",
+		name: "inferred type from default value - array",
 		before: &v1beta1.ParamSpec{
-			Name:    "parametername",
-			Default: v1beta1.NewArrayOrString("an", "array"),
+			Name: "parametername",
+			Default: &v1beta1.ArrayOrString{
+				ArrayVal: []string{"array"},
+			},
+		},
+		defaultsApplied: &v1beta1.ParamSpec{
+			Name: "parametername",
+			Type: v1beta1.ParamTypeArray,
+			Default: &v1beta1.ArrayOrString{
+				ArrayVal: []string{"array"},
+			},
+		},
+	}, {
+		name: "inferred type from default value - string",
+		before: &v1beta1.ParamSpec{
+			Name: "parametername",
+			Default: &v1beta1.ArrayOrString{
+				StringVal: "an",
+			},
 		},
 		defaultsApplied: &v1beta1.ParamSpec{
-			Name:    "parametername",
-			Type:    v1beta1.ParamTypeArray,
-			Default: v1beta1.NewArrayOrString("an", "array"),
+			Name: "parametername",
+			Type: v1beta1.ParamTypeString,
+			Default: &v1beta1.ArrayOrString{
+				StringVal: "an",
+			},
 		},
 	}, {
 		name: "fully defined ParamSpec",
 		before: &v1beta1.ParamSpec{
 			Name:        "parametername",
 			Type:        v1beta1.ParamTypeArray,
 			Description: "a description",
-			Default:     v1beta1.NewArrayOrString("an", "array"),
+			Default: &v1beta1.ArrayOrString{
+				ArrayVal: []string{"array"},
+			},
 		},
 		defaultsApplied: &v1beta1.ParamSpec{
 			Name:        "parametername",
 			Type:        v1beta1.ParamTypeArray,
 			Description: "a description",
-			Default:     v1beta1.NewArrayOrString("an", "array"),
+			Default: &v1beta1.ArrayOrString{
+				ArrayVal: []string{"array"},
+			},
 		},
 	}}
 	for _, tc := range tests {

pkg/apis/pipeline/v1beta1/pipeline_defaults_test.go

@@ -81,6 +81,21 @@ func TestPipelineSpec_SetDefaults(t *testing.T) {
 				Name: "string-param", Type: v1beta1.ParamTypeString,
 			}},
 		},
+	}, {
+		desc: "param type - param type must be derived based on the default value " + string(v1beta1.ParamTypeString),
+		ps: &v1beta1.PipelineSpec{
+			Params: []v1beta1.ParamSpec{{
+				Name: "string-param",
+				Default: &v1beta1.ArrayOrString{
+					StringVal: "foo",
+				},
+			}},
+		},
+		want: &v1beta1.PipelineSpec{
+			Params: []v1beta1.ParamSpec{{
+				Name: "string-param", Type: v1beta1.ParamTypeString, Default: &v1beta1.ArrayOrString{StringVal: "foo"},
+			}},
+		},
 	}, {
 		desc: "pipeline task with taskSpec - default param type must be " + string(v1beta1.ParamTypeString),
 		ps: &v1beta1.PipelineSpec{