The test suite should consider a 0x0 empty matrix (as given by y = []) as equivalent to a 1x0 empty matrix (which results from the code above it
Test  Status  Code Input and Output 

1  Pass 
%%
x = [];
y_correct = [];
assert(isequal(common_by_row(x),y_correct))
y =
[]
n =
0

2  Pass 
%%
x = [1e100; 1e100];
y_correct = [1e100];
assert(isequal(common_by_row(x),y_correct))
y =
[]
n =
2
y =
1.0000e+100
y =
1.0000e+100

3  Pass 
%%
x = [1; 2];
y_correct = [];
assert(isequal(common_by_row(x),y_correct))
y =
[]
n =
2
y =
1
y =
Empty matrix: 1by0
y =
[]

4  Pass 
%%
x = ones(10);
y_correct = [1];
assert(isequal(common_by_row(x),y_correct))
y =
[]
n =
10
y =
1 1 1 1 1 1 1 1 1 1
y =
1
y =
1
y =
1
y =
1
y =
1
y =
1
y =
1
y =
1
y =
1

5  Pass 
%%
x = magic(10);
y_correct = [];
assert(isequal(common_by_row(x),y_correct))
y =
[]
n =
10
y =
92 99 1 8 15 67 74 51 58 40
y =
Empty matrix: 1by0
y =
Empty matrix: 1by0
y =
Empty matrix: 1by0
y =
Empty matrix: 1by0
y =
Empty matrix: 1by0
y =
Empty matrix: 1by0
y =
Empty matrix: 1by0
y =
Empty matrix: 1by0
y =
Empty matrix: 1by0
y =
[]

6  Pass 
%%
x = wilkinson(9);
y_correct = [0 1];
assert(isequal(common_by_row(x),y_correct))
y =
[]
n =
9
y =
4 1 0 0 0 0 0 0 0
y =
0 1
y =
0 1
y =
0 1
y =
0 1
y =
0 1
y =
0 1
y =
0 1
y =
0 1

7  Pass 
%%
x = [3 2 1 NaN; NaN 0 2 3];
y_correct = [2 3];
assert(isequal(common_by_row(x),y_correct))
y =
[]
n =
2
y =
3 2 1 NaN
y =
2 3

Back to basics 23  Triangular matrix
534 Solvers
Multiples of a Number in a Given Range
141 Solvers
146 Solvers
251 Solvers
264 Solvers